rhg-annotate: support whitespace options This adds support to rhg annotate for all the whitespace options: -w, --ignore-all-space -b, --ignore-space-change -B, --ignore-blank-lines -Z, --ignore-space-at-eol Note that --ignore-blank-lines has no effect on annotate so it is ignored. You can see this in dagop.py _annotepair which only checks if blocks are '=' or not, whereas the effect of --ignore-blank-lines is to change some '!' into '~'. When the other 3 are combined, we use the strongest option since -w implies -b and -b implies -Z. This is not explicit in the Python implementation, but I have verified that's how it behaves.