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