Do a rebuild from scratch only if requested. This allows fast local testing of new or changes test cases.
Don't need to call gcov ourselves as this is done by codecov too.
* enable coverage reports from gcc and disable optimizations via option to configure
* install googletest library into buildcache
* script to compile and run unit tests using cmake
* first set of unit tests originaly contributed by Keith Uplinger
There are several hardcoded paths and assumptions made in order to get this working on Travis CI. New tooling is using cmake for cross platform builds and as such is not easy to use with an autotools based system.
It's not ideal but better than nothing.