Request for new cmake macro for 4.0

[Christian Ehrlicher]

Some days ago the MacOS team found out that they need a macro to add
icons to their application. We (kde-windows) already have
KDE4_ADD_WIN32_APP_ICON and therefore it would be nice to create a
unique KDE4_ADD_APP_ICON for all platforms (where it's supported).

Our idea is to replace KDE4_ADD_WIN32_APP_ICON (which is only used by
kde-edu and kde-games) with KDE4_ADD_APP_ICON before 4.0.
On the other side I don't mind supporting KDE4_ADD_WIN32_APP_ICON for
4.x - it depends on how fast the macos team needs it's macro.

As only SaroEngels added this macro, the change should not break
anything - it's only a name change afaics.



Christian