fix right mouse click
Fixes for Xcode warnings with no Visage, explanatory comments for Model's
base geometry pointer.
Fixed some left/right issues.
We need libc++, not libc++abi.
Merge pull request #2026 from ZappoMan/rightbuttonbug

fix right mouse click
Merge pull request #2028 from ey6es/master

Fixes for Xcode warnings without Visage, explanatory comment for Model's base geometry, left/right fixes.
Merge branch 'master' of https://github.com/worklist/hifi into js_clipboard