CordobaZombie0.1: commit from wrong branch, adding sound to buttons.

I did this from here because branch cordobazombie0.1 had recently been merged
with this one (resources_config_window), and since we're close to deployment
I didn't want to break things in the main branch.

AGUS: if changes are correct please merge this to cordobazombie0.1
Merge branch 'cordobazombie0.1' into resources_config_window
ResourcesConfigWindow: merging with branch cordobazombie0.1

Updating files of this branch to start migrating to Qt 4.8 in Linux.
ResourcesConfigWindow: unifying Qt support, now both Windows and Linux use Qt4
ResourcesConfigWindow: fixed changing frequencies issue.

Available display frequencies now get updated every time the resolution
is changed by the user. See MantisBT issue #344 for details.
ResourcesConfigWindow: using Qt resources to load background image

We now can load any image using Qt resources system.
How-to code can be seen in files AutoGen.cmake and CbaZombieConfigDialog.{cpp,qrc}
For details check MantisBT issue #346.