move endpoint generation into right click file context menu.

Change-Id: I423982b4e73f5967e865a6e53e290b0d2aa78780

https://screenshot.googleplex.com/JFUv9xySox.png (Cloud Tools are gone from Tools Menu)
https://screenshot.googleplex.com/YwKiqG9GHG.png (added to project nav right click)
https://screenshot.googleplex.com/XfKOarrviG.png (added to editor right click)

Bug:17326951
Merge "move endpoint generation into right click file context menu." into idea133
refactored AppEngineUtils to only require a module param and to delegate to AppEngineGradleFacet

Change-Id: I64acd796bfbff63c4a056f9929061ec7b2ac64b2
Merge "refactored AppEngineUtils to only require a module param and to delegate to AppEngineGradleFacet" into idea133