revsetlang: move quoting function to not be a closure I'm about to change the implementation here and I'd like to add some doctests, which means this needs to not be hidden inside another function.

revsetlang: portably bytestring-ify another pair of int() calls

checkcode: enforce lowercase for extension docstring title This will ensure new extensions are consistent and `hg help -e` has a consistent output. I have to add a new group since the normal "pypats" will be filtered by "pyfilters", which will remove comments and docstrings.