Lcov coverage reports
I've implemented a makefile target to generate pretty html output as discussed from 0 on tor-dev. This target basically resets any coverage files, runs ./src/test/test (only) and then generates lcov's internal coverage report, followed by genhtml's HTML coverage report. I've also added a stanza on using lcov via this make target to doc/HACKING.
The implementation of coverage diffs using lcov is something I'm investigating, and will post back here when I have further progress. Initially, i'll just implement the kludge the lcov mailing list via Nick suggests at 1.