Text groups for better compression

Change-Id: I42575d934d6b1edb77b355d10e9047fe54961c59
Removed check for trailing zero in decompressed string

With compressed groups, missing trailing zero is problematic.
On the other hand, added trailing zero is now okay.

Change-Id: Ia368b7ef2a198ee327029704e0a19f5b4ae7f84f
Fixed compilation on Linux by moving constants to .cpp

Change-Id: I76cec79142f3b2a85e36b8e61c8a780dc061dd66