mq: don't use len(list) unless necessary

mq: find_series() simplify and don't use regexps

mq: fix coding style (missing space)

mq: qsave creates entries with the left part empty (':patchname')

mq: simplify statusentry(), fix restore broken by ee48e5ef8753

mq: use context API

mq: simplify qparents calculation

mq: simplify commit message generation

mq: avoid many hex/bin conversions, keep the binary node when possible

rebase: add option to not commit after a collapsing This option is useful when other extensions (e.g., pbranch) want to use rebase --collapse and append other things before committing. This is not intended to be used from command line.