	Create a new TopGit-controlled topic branch of a given name
	(required argument) and switch to it. If no dependencies
	are specified (by extra arguments passed after the first one),
	the current branch is assumed to be the only dependency.

	After `tg create`, you should insert the patch description
	to the '.topmsg' file, which will already contain some
	prefilled bits. You can set topgit.to, topgit.cc and topgit.bcc
	configuration variables in order to have `tg create`
	add these headers with given default values to '.topmsg'.

	The main task of `tg create` is to set up the topic branch
	base from the dependencies. This may fail due to merge conflicts.
	In that case, after you commit the conflicts resolution,
	you should call `tg create` again (without any arguments);
	it will detect that you are on a topic branch base ref and
	resume the topic branch creation operation.

	In an alternative use case, if '-r BRANCH' is given instead
	of dependency list, the topic branch is created based on
	the given remote branch.

