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
only show the generate endpoint action when looking at a java file which is part of an app engine backend.

Change-Id: I47fb70fb598b1fab22e76938f60b137d3de394ba
Merge "only show the generate endpoint action when looking at a java file which is part of an app engine backend." into idea133
merge in ub-tools-idea133-release history after reset to fe1a105dc035105afce369510a6fd6aa7c194418