Create project build directory in temp directory

 The build directory will be created in the system temp directory.
 Added two options:
  --project-dir=DIR Allow saving the build directory to a location
  --project-only      Skip creation of APKs.  Just save the project dir
 Modified make_apk_test.py to include option "--project_dir=." in tests

 Bug=XWALK-2394
nit, remove this empty at end of a file.