Rename QtMacExtras_{master,dev}_Integration

Switching to use the dev/stable/release scheme in the future.

Change-Id: Ia10412169a639390cfd6d89fe63c9234067531a4
Reviewed-by: Liang Qi <liang.qi@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Simo Fält <simo.falt@digia.com>