control.Coverage._init: check "source" is a directory, not just it exists; there could be a file with that name
control.Coverage._init: check "source" is a directory, not just it exists; there could be a file with that name

--HG--
branch : check-source-isdir

hugovk/coveragepy,nedbat/coveragepy,blueyed/coveragepy,nedbat/coveragepy,nedbat/coveragepy,hugovk/coveragepy,hugovk/coveragepy,blueyed/coveragepy,hugovk/coveragepy,blueyed/coveragepy,nedbat/coveragepy,blueyed/coveragepy,nedbat/coveragepy,blueyed/coveragepy,hugovk/coveragepy