Add 'profile' build configuration and code coverage tools

This pull request adds a 'Profile' configuration to the build system (currently only functional for GCC/Clang builds: it is the same as 'Debug' but with code coverage instrumentation enabled), and the 'lcov' and 'lcov_cobertura' tools, along with some helper scripts. The result of all of this can be seen at:

http://ci.openbloomberg.com/jenkins/job/BSL-QC/33/cobertura