standalone linux app nearly ready

also made several fixes that apply to the OSX app

standalone/linux/git-annex-webapp

@@ -0,0 +1,25 @@
+#!/bin/sh
+base="$(dirname $0)"
+if [ ! -d "$base" ]; then
+	echo "** cannot find base directory (I seem to be $0)" >&2
+	exit 1
+fi
+if [ ! -e "$base/runshell" ]; then
+	echo "** cannot find $base/runshell" >&2
+	exit 1
+fi
+
+# Get absolute path to base, to avoid breakage when things change directories.
+orig="$(pwd)"
+cd "$base"
+base="$(pwd)"
+cd "$orig"
+
+# If this is a standalone app, set a variable that git-annex can use to
+# install itself.
+if [ -e "$base/bin/git-annex" ]; then
+	GIT_ANNEX_APP_BASE="$base"
+	export GIT_ANNEX_APP_BASE
+fi
+
+"$base/runshell" git-annex webapp "$@"