Path to libgmock

Since Google says that it is not recommended to install a pre-compiled version of Google Test distributions starts to remove the pre-provide versions from their repositories (at least Debian and Ubuntu).
I've added 2 arguments to your cmock-config script to be able to pass the paths to libgmock and libgtest.
I've also added two variables to the Makefile of your test project (GMOCK and GTEST) to be able to pass the paths into the test build.

I would also suggest to remove the install and uninstall target from the Makefile. Because when there are no pre-compiled versions of the Google libs, I would recommend to integrate the souce code of the libs into the project that is tested. That would make the install target redundant.

Regards Moritz

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* [Why is it not recommended to install a pre-compiled copy of Google Test][4]
[4]: https://code.google.com/p/googletest/wiki/FAQ#Why_is_it_not_recommended_to_install_a_pre-compiled_copy_of_Goog