SoundRecorder: Bring out of gingerbread days

* Include all icons for modern screen resolutions
* New app icon
* Solid actionbar
* Kill the old button style
* Kill the timer background
* Always show the VUMeter
* Add missing icon states in recording status message
* Don't mess with actionbar title, we already describe the recording status right below that
* Disable recording button when recording is finished and while playback is in progress
* Improve some strings

TODO:
* Provide a better landscape layout
* Allow pausing while playback of the latest recording is in progress
* Test on different screen resolutions
* Replace VUMeter with android-visaliser(?)

Screenshots: http://imgur.com/a/UEN5j#0

Change-Id: I945a07d05709280b3de0503f52486cd7d0341bfe