Switch from google-glog to Boost.Log.

In addition to living up to the Boost association of this project,
it also supports Android (which, ironically, google-glog does not).
Fix linking of tests.
Simplify src/msgpack/rpc/CMakeLists.txt.

It's the same project as its parent so it should adopt the same
version numbers instead of trying to reinitialize everything.
Merge pull request #3 from jpetso/master

Switch to Boost.Log from google-glog, and some more clean-ups