add new status command

This works for both direct and indirect mode.

It may need some performance tuning.

Note that unlike git status, it only shows the status of the work tree, not
the status of the index. So only one status letter, not two .. and since
files that have been added and not yet committed do not differ between the
work tree and the index, they are not shown. Might want to add display of
the index vs the last commit eventually.

This commit was sponsored by an unknown bitcoin contributor, whose
contribution as been going up lately! ;)

doc/git-annex.mdwn

@@ -103,6 +103,13 @@ subdirectories).
 
   To avoid contacting the remote to check if it has every file, specify `--fast`
 
+* `status` [path ...]`
+
+  Similar to `git status --short`, displays the status of the files in the
+  working tree. Shows files that are not checked into git, files that
+  have been deleted, and files that have been modified. 
+  Particulary useful in direct mode.
+
 * `unlock [path ...]`
 
   Normally, the content of annexed files is protected from being changed.
@@ -563,10 +570,6 @@ subdirectories).
 
 # QUERY COMMANDS
 
-* `version`
-
-  Shows the version of git-annex, as well as repository version information.
-
 * `find [path ...]`
 
   Outputs a list of annexed files in the specified path. With no path,
@@ -624,6 +627,9 @@ subdirectories).
   Then run:
 
         	git annex info --fast . --not --in here
+* `version`
+
+  Shows the version of git-annex, as well as repository version information.
 
 * `map`