#165841: Can`t deactivate particular module in shared installation

http://openide.netbeans.org/issues/show_bug.cgi?id=165841

In case shared installation is read only, its modules cannot be 
activated/deactivated.

Problem was caused by redesign of Tools/Plugins to have 
Activate/Deactivate/Uninstall button next to each other. In this process the 
selection logic was kept unchanged and as such it applies to uninstall 
operation. Obviously it makes no sense to try to uninstall read only module.

The fix is to change the logic and allow modules to be selected even if they 
are read only (just disable Uninstall action in such situation).

-jst