Remove unneeded sound modules and cleanup the .pro file

The sound modules weren't used in webappmanager, so can be removed,
plus the references to them in the .pro file.
Also removed references to unused #defines in the .pro file.

When built with Qt5, now includes QtWebkitWidget in the pri files.

Removed reference to serviceinstaller from the device.pri file

Open-webOS-DCO-1.0-Signed-off-by: Roger Stringer <roger.stringer@palm.com>

Change-Id: I2e43da62427722e2953266e56329d1042e439886