doc: add git-remote-bzr/hg documentation

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: fix remote-hg-hg-git python path

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
test: cleanup remote-hg-hg-git test

We don't need hgext.bookmarks since a long long time (ever).

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>