separate import lines from mercurial and general python modules

manpage build: fail early when xmlto is not available When we try to build manpages with xmlto and sed, but xmlto is missing fail at the xmlto stage. Otherwise, one may run `cd doc; make' and miss the warnings like: xmlto: not found sed: hg.1: No such file or directory and end up with empty files installed as manpages.

dirstate: translate forgotten string

util: overwrite sha1 and _fastsha1

test-convert-bzr: tweak sed hack to preserve timezone in 'bzr log' output

zeroconf: remove unwarranted execute bit

test-convert-bzr: use sed instead of awk The run-tests.py script has a list of required tools and awk is not one of them -- luckily it could be replaced by sed in this case.

convert/bzr: handle Bazaar timestamps correctly (issue1652).

dispatch: remember loaded extensions in a real set

gpg: use reverse kwarg to sort sigs in reversed order