Updated to coverage.py 3.6.
Optionally allow people to revert to the louder style of coverage missing reports.
Specify the .coveragerc; don't use os.chdir().

This solves a bug: sometimes the omit attribute was not being loaded
because we were depending on the current directory to find the
.coveragerc file and the plugin called os.chdir() *after* reading
the config file. The better solution is to not mess with the
current directory and always specify the config file.
Better name for signal file: ".coverage-noisy"
Merge git://github.com/niclas-ahden/SublimePythonCoverage
Initial port of Python Coverage to Sublime Text 3 / Python3