mq: don't commit local changes on pushing empty patch (issue1087)

remove trailing spaces

mq: add a little documentation on qpush -f

ignore *.pyd files *.c modules on Windows are compiled to *.pyd

Merge with crew-stable, fix test output

Merge with crew-stable

replace usage of os.popen() with util.popen() To make this possible, I added a mode parameter to both implementations of util.popen(), defaulting to 'r' (as it does in the Python stdlib).

test-merge-internal-tools-pattern: make executable

convert: fix svn file copy detection code

convert: fix svn branch source detection corner case It was confused by composite-looking revisions made by copy + remove.