Nested Trees and History after Splitting

[A. S. Budden]

Dear all,

I have just split several parts of my project into separate "library
modules" that will be used in a number of projects.  However, despite
the code size being less than 700 k (in one example) and the files
having only changed about once in the entire project history, the .bzr
folder is 19 MB.  This is because the 'split' project has taken all of
the history of the parent project, including the history of all the
files that have absolutely nothing to do with the library module.
Given that the modules may be downloaded over the network for lots of
projects and there may be quite a lot of library modules, this could
result in quite a long check-out time: if one project requires five of
the library modules, it'll have to download five copies of the
original project's history, taking about 100 MB!

Is there any way to delete all history that doesn't relate to the
files that are present in the working directory at the moment?

On a separate note, I've been reading
http://bazaar-vcs.org/NestedTreesDesign and we are quite keen to use
this.  Where we have library modules, they will be kept in a
particular place on our shared repository but it would be good for the
projects using those libraries to have a built in way to refer to
them.  It would be really nice if the project check-out from the
shared repository automatically grabbed the appropriate version of the
library modules at the same time.  Obviously this could be bodged with
a script to retrieve the modules if they're not present when the
project is compiled, but the "join --reference" thing sounded much
more promising.  The option "--reference" doesn't seem to be mentioned
in "bzr help join" though and when I tried it, it just did a
conventional join (although there was no error about an unsupported
command).  Am I doing something wrong?

Also, are the split and join options likely to go into TortoiseBzr?
Most of my coworkers prefer GUIs and if we are going to switch from
the hideous PVCS to the wonderful Bazaar, they'll probably need to do
everything in GUI land!

Thanks in advance,

Al

-- 
http://sites.google.com/site/abudden