Reorganise repository layout

[Adam Mercer]

Hi

My repository is currently organized as follows:

repo:
- .bzr
- project_1
- project_2
- project_3

i.e. I have a single repository containing multiple projects, it is
possible to change my repository layout so that each project directory
is a bzr repository with its own .bzr directory - yet still
maintaining version history? i.e. I would like the layout to be
something like

root:
- project_1:
  | - .bzr
- project_2:
  | - .bzr
- project_3:
  | - .bzr

Cheers

Adam