Revision 780326

Added code coverage report generation target.

To generate reports:

    # Assuming etap is installed
    $ cd /path/to/couchdb
    $ ./bootstrap && ERLC_FLAGS=+debug_info ./configure && make cover

You can browse the report by opening ./cover/index.html in your html consuming software of choice.

Shoutout to Nick Gerakines in THANKS for helping with etap and testing in general.