PATCH: Add bzr building support

[Geert Janssens]

On Saturday 20 February 2010, Jesse Weinstein wrote:
> This patch allows gnucash to be built from bzr repositories, by
> modifying gnc-svnversion to support bzr.
> 
> I previously, incorrectly, sent this to the list mixed in with another
> patch; I'm resending it separately, as suggested on IRC, for ease of
> commenting.
> 
> Jesse
> 
Applied (r18692). Thanks a lot!

Geert