Add a local build setup

to make "./gradlew build" work on a fresh clone, even if you don't
have the passwords for the official release key.
This will also enable any developer to test the release version of the
application.

When keys are not provided in squeezer.properties the app will be build
just like the official release version, but signed with a local release key
with password "squeezer" for the key and the keystore.
Parse status line from LMS more conservatively

This will fix a reported crash from bugsense.

When the status line come, from some servers  or in some circomstances,
the token for the playing mode (play/pause/stop), may not present.

To handle this and because this is dependant on the server version, and
at any rate beyond our control, Squeezer now checks if mode, shuffle and
repeat status are present, and if not, doesn't update the internal player
state or the UI.