Adding correct permissions to marytts-5.0 install target

Fixing #53
Fixing #52:
* Enabling selection of `en_GB` locale
* Setting `en_GB` as default locale because the default language is part of that

Fixing #50:
* removed autostart from action server

Additional bugfix:
* If an empty string is pushied a warning will be diplayed and the ervice or action server report failure. This prevents mary from crashing when trying to say nothing.
Merge branch 'hydro-devel' of http://github.com/strands-project/strands_ui into hydro-devel
Merge pull request #54 from cdondrup/hydro-devel

[mary_tts] multiple bug fixes