obslog: colorize the description diff shown in obslog -p This patch colorizes the description diff shown in `hg obslog -p`. The labels for the header are different from that of the patch as the main header which says `diff -r <somehash> -r <somehash> <filename>`. Next patch will hack to add that.

obslog: colorize the patch shown using `hg obslog -p` This patch adds color support to the patch shown in obslog command.

topic: suggest using topic when user creates a new head on branch This patch adds a message to use topics when user creates a new head on a branch.

changelog: update changelog with some of the benefit from the new format

evolve: use better words in conflict markers of `hg evolve` Though we call merge.graft internally, we still have the functionality to pass the words we want to show up in conflict markers. So let's use better words here.

tests: add a test demonstrating we still use graft in conflict markers This patch adds a test which shows that we still use the word graft in the conflict markers. Next patch will start using evolve instead of graft.

evolve: remove the old functions for writing evolvestate Previous patch made all the users of these functions to use the evolvestate class and now they are not required. Let's remove them.