Move message and conversation storage to IndexedDB

Getting up and running with IndexedDB was pretty easy, thanks to
backbone. The tricky part was making reads and writes asynchronous.
In that process I did some refactoring on Whisper.Threads, which
has been renamed Conversations for consistency with the view names.

This change also adds the unlimitedStorage permission.

test/models/conversations_test.js

@@ -0,0 +1,149 @@
+/* vim: ts=4:sw=4:expandtab
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function () {
+    'use strict';
+    function clear(done) {
+        var convos = new Whisper.ConversationCollection();
+        return convos.fetch().then(function() {
+            convos.destroyAll().then(function() {
+                var messages = new Whisper.MessageCollection();
+                return messages.fetch().then(function() {
+                    messages.destroyAll().then(function() {
+                        done();
+                    });
+                });
+            });
+        });
+    }
+
+    var attributes = { type: 'outgoing',
+                        body: 'hi',
+                        conversationId: 'foo',
+                        attachments: [],
+                        timestamp: new Date().getTime() };
+
+    describe('ConversationCollection', function() {
+        before(clear);
+        after(clear);
+
+        it('adds without saving', function() {
+            var convos = new Whisper.ConversationCollection();
+            var message = convos.add(attributes);
+            assert.notEqual(convos.length, 0);
+
+            var convos = new Whisper.ConversationCollection();
+            assert.strictEqual(convos.length, 0);
+        });
+
+        it('saves asynchronously', function(done) {
+            new Whisper.ConversationCollection().add(attributes).save().then(done);
+        });
+
+        it('fetches persistent convos', function(done) {
+            var convos = new Whisper.ConversationCollection();
+            assert.strictEqual(convos.length, 0);
+            convos.fetch().then(function() {
+                var m = convos.at(0).attributes;
+                _.each(attributes, function(val, key) {
+                    assert.deepEqual(m[key], val);
+                });
+                done();
+            });
+        });
+
+        it('destroys persistent convos', function(done) {
+            var convos = new Whisper.ConversationCollection();
+            convos.fetch().then(function() {
+                convos.destroyAll().then(function() {
+                    var convos = new Whisper.ConversationCollection();
+                    convos.fetch().then(function() {
+                        assert.strictEqual(convos.length, 0);
+                        done();
+                    });
+                });
+            });
+        });
+
+        it('should be ordered newest to oldest', function() {
+            var conversations = new Whisper.ConversationCollection();
+            // Timestamps
+            var today = new Date();
+            var tomorrow = new Date();
+            tomorrow.setDate(today.getDate()+1);
+
+            // Add convos
+            conversations.add({ timestamp: today });
+            conversations.add({ timestamp: tomorrow });
+
+            var models = conversations.models;
+            var firstTimestamp = models[0].get('timestamp').getTime();
+            var secondTimestamp = models[1].get('timestamp').getTime();
+
+            // Compare timestamps
+            assert(firstTimestamp > secondTimestamp);
+        });
+    });
+
+    describe('Conversation', function() {
+        var attributes = { type: 'private', id: 'foobar' };
+        before(function(done) {
+            var convo = new Whisper.ConversationCollection().add(attributes);
+            convo.save().then(function() {
+                var message = convo.messages().add({body: 'hello world', conversationId: convo.id});
+                message.save().then(done)
+            });
+        });
+        after(clear);
+
+        it('contains its own messages', function (done) {
+            var convo = new Whisper.ConversationCollection().add({id: 'foobar'});
+            convo.fetch().then(function() {
+                assert.notEqual(convo.messages().length, 0);
+                done();
+            });
+        });
+
+        it('contains only its own messages', function (done) {
+            var convo = new Whisper.ConversationCollection().add({id: 'barfoo'});
+            convo.fetch().then(function() {
+                assert.strictEqual(convo.messages().length, 0);
+                done();
+            });
+        });
+
+        it('has most recent messages first', function(done) {
+            var convo = new Whisper.ConversationCollection().add({id: 'barfoo'});
+            convo.messages().add({
+                body: 'first message',
+                conversationId: convo.id,
+                timestamp: new Date().getTime() - 5000
+            }).save().then(function() {
+                convo.messages().add({
+                    body: 'second message',
+                    conversationId: convo.id
+                }).save().then(function() {
+                    convo.fetch().then(function() {
+                        assert.strictEqual(convo.messages().at(0).get('body'), 'second message');
+                        assert.strictEqual(convo.messages().at(1).get('body'), 'first message');
+                        done();
+                    });
+                });
+            });
+        });
+    });
+
+})();;