patchbomb: add -B option to select a bookmark Add the -B/--bookmark option to select a bookmark whose changesets and its ancestors will be selected unless a new bookmark/head is found. This is inspired by hg strip -B option.

test: add the mirror push race case for non-contiguous branch head We check case where the raced push update that a head through another named branch while the racing push update that same head.

test: add a push race case where non-contiguous branch head are created We check case where the raced push an update to branch default head while the racing push update that same head but through another named branch.

test: add a push race case where the raced push touch multiple heads We check case where the raced push update all heads while the racing push update one of them.

test: add a push race case where racing push touches multiple heads We check case where the raced push updates a head while the racing push update all of them.

test: add a push race case where racing push create a new named branch This is the mirror case from the previos one. We check case where the raced push update a head while the racing push create a new named branch as a children of that updated head.