[ANN][PLUGIN] graphical diff using kompare

[Stephen Ward]

Hi, 

Following in the footsteps of the vimdiff plugin, I've added a new plugin to 
use the KDE 'kompare' tool for graphical diffs.   This version supports 
recursive diffs, and by default it compares the whole working tree against 
the basis tree.  Examples include:

bzr kompare                         # diff the whole tree
bzr kompare .                       # recursive diff from current directory
bzr kompare -r last:5 FILE          # diff FILE against revision -5
bzr kompare -r 3..5 FILE            # diff revisions 3..5 of FILE
bzr kompare main dev                # diff two directories (or branches)

This plugin was written against the bzr.dev branch, so it will not work with 
the older 0.7 version; if there is enough demand, I can back-port it to the 
old API easily enough.

The plugin can be obtained as a bzr branch, or as a tarball, from:

   http://mysite.verizon.net/sward.dev/projects/bzr_kompare
   http://mysite.verizon.net/sward.dev/projects/bzr_kompare.tar.gz

and I've added it to the plugin registry.

Let me know if you think of any needful features, or if you have suggestions 
for better ways to make use of the bzrlib API for this purpose.

-- Steve