Cool new easy-to-update Plugins Guide - add information to extmerge page.

[David Ingamells]

Ian,
I (any maybe others too ;-) ) would appreciate it if a literate version 
of following information could be added to the documentation of extmerge 
instead of the very helpful "See extmerge/extmerge.py for the syntax." 
which advice is even more helpful when one considers that when extmerge 
is installed the file is called "<plugins>/extmerge/__init__.py".

This is the information from the .py file:

# The same syntax as in mergetools below, can be used in external_merge
# in bazaar.conf
# %b = base  (foo.BASE)
# %t = this  (foo.THIS)
# %o = other (foo.OTHER)
# %r = resolved file (aka output file) (foo)

mergetools = [
        'kdiff3 --output %r %b %t %o',
        'xxdiff -m -O -M %r %t %b %o',
        'opendiff %t %o -ancestor %b -merge %r']

cheers,
David.