Fix gtest intermediate directory

Intermediate directory for gtest pointed at wrong dir, which caused
warnings during compilation.

Verification:
    Batch build entire solution. Make sure, that contents of Obj dir are
    organised within following pattern:
        Obj/<project_name>/<platform>/<configuration>/...

Change-Id: Ibdc12f2c3c0f9b99c8f5179b1cf773c071ed92fc
Import AntTweakBar 1.16 source

This contains newest entire AntTweakBar source code and adds .vcxproj for
compilation within Deps repo.

Verification:
    Successful batch build.

Change-Id: Ic6955144873713aeabb9e0898658274e12ea7c24