Add test coverage option to CMake (RUN_COVERAGE) and update Travis script to run the option.
Update main CMakeLists.txt with option to run test coverage analysis (RUN_TEST_COVERAGE).
Update readme with description of RUN_TEST_COVERAGE option.
Update Travis script to run test coverage using coveralls-lcov (https://github.com/okkez/coveralls-lcov) and push the results to Coveralls.io.
Pull in latest changes to CodeCoverage CMake module.
Simplify Travis script for Coveralls.io by only building against GCC with no matrix environment variables. Add Coveralls.io badge to readme.
Switch Coveralls.io interface in Travis script to Lcoveralls (https://github.com/pcolby/lcoveralls).
Make coverage script after_success in Travis script dependent on if the compiler is GCC.
dd COVERAGE_EXTRACT variable to extract directories to include in coverage analysis and pull in update to CodeCoverage CMake module.
Fix problem with extracting code for coverage analysis.