Log Message:
Changes 2.2.0:
This release adds support for use of the gflags library as external dependency \ 
not only in projects using CMake, but also Bazel, or pkg-config. One new minor \ 
feature is added in this release: when a command flag argument contains dashes, \ 
these are implicitly converted to underscores. This is to allow those used to \ 
separate words of the flag name by dashes to do so, while the flag variable \ 
names are required to use underscores.

Memory leaks reported by valgrind should be resolved by this release.
This release fixes build errors with MS Visual Studio 2015.