Clean up tree of a project using bzr

[matiyam]

Hi!

I have a project where i use bzr for version control.

When i started it, i added a directory which contains lots of big files that
now i have realised i don't need them to be versioned.

I know i can do a "bzr rm directory", but then i guess they would be wasting
space in the .bzr directory.

Id there a way of (maybe branching, i don't know) cleaning / creating a new
branch without this directory, but preserving the history of changes in the
rest of the tree?

Thanks a lot for your attention, and for such a useful tool!!

-- M