bug JBIDE-16257 - Cordova Plug-in Discovery wizard should have option to
show already installed plug-ins as disabled 

Adds a new show installed checkbox. If selected catalog viewer will
display the installed plugins as grayed out and not selectable. This
change also removes the selection highlights which have no use
bug JBIDE-16578 - NPE when creating Hybrid Mobile Project

Returns empty engine list of the library folder has not been created yet