Add optimized Qt configure flags

Add -skip statements for unneeded modules. Also disable Qt features
we don't need, including -developer-build.

Change-Id: Ic82d8c0ef9f8cf172a1623268322b028fc74853c
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Christian Stenger <christian.stenger@digia.com>