Switch copyright license messages to LGPL

I don't know why these header files had a copyright message of Apache.
They should have been LGPL to be consistent with the rest of MRI.
Make gcov work with .cpp source files as well

My last commit fixed the CPPUTEST_USE_VPATH for .c files but was still
broken for .cpp files.

I found that I needed to make this fix once I treated the test/mocks as
source code to be measured for code coverage.
Refactor platformMocks code

This was mostly just so that I would know where I am starting out as I
expand the unit tests for the MRI core code.