log: pack filematcher and hunksfilter into changesetdiffer object This is just a way of getting rid of clumsy makefilematcher/makehunksfilter arguments. There might be a better abstraction, but I don't think this is bad. This makes filematcher and hunksfilter available by default, but that should be fine.

log: drop dead code to concatenate --line-range patterns and pats It's disabled since 2e45bbd3db7b, and the current implementation is unlikely to be reused.