port basic tests from robo-tests/ to an Android Test Project

This is easily runnable using Eclipse, ant, and Jenkins.  It probably works
elsewhere as well, since this is the official way of running tests using
the Android tools:

https://developer.android.com/tools/testing/
show error message if sharing data when all accounts are offline

Previously, if a SEND/Share Intent was sent to ChatSecure when it was
offline, ChatSecure would just show a blank white screen.  That screen was
ImUrlActivity doing nothing at all.  When all accounts are offline, this
commit makes the blank white screen go away, and gives an error message in
a Toast.
make ChatSecure claim .ofcaes files that are opened in file managers

The IntentFilters do file associations very poorly.  These crazy hacks are
the only way I've been able to get file associations working when defining
custom types that do not have built-in mime types, according to Android
itself.
show error message if shared URL is not understood

Avoid the dreaded blank white screen!
standardize on IocVfs.isVfsUri(Uri) for testing VFS URLs

Everywhere that IocVfs.isVfsScheme() was used, it was operating on a Uri
instance.
send contacts that are shared to ChatSecure

This reads the ContentProvider into a VCard in the VFS, then sends it using
OTRDATA.  It also eliminates another mystery blank, white screen in
response to sharing something to ChatSecure.
strip down inline Audio Player to make it more responsive

Now that it is not showing a UI at all, it really does not need the
overhead of an Activity.  This also runs the "prepare" phase async so that
it should not block UI updates.  The inline play button should pdate
make MessageView also guess the MIME type to display uploaded media

If the user sends an image or audio file via Send File, then it should
still show up inline and be playable.