Interface with discussion media (4) by difference bridge

[Thomas von der Elbe]

Hello folks,

the difference bridge is working and has cherry-picking merge controls
now :-)

If you go to the sandbox position of Test-a and click "Compare to
candidate" it will list all the single differences to the position of
his candidate (Test-b):
http://u.zelea.com/w/User:Test-a-ZeleaCom/Sys/p/sandbox

Either one of them can now easily pick ideas from the other. They just
choose the ones they like and click "Patch", which immediatly pulls
them into their position in the wiki. It's really fun! You can try it
out, if you log in as one of them. (To log in as Test-a just type "a"
in the alias login field.)

Additionally each difference can be linked to separatly now. So an
example for a typical post in an email-list now could be :

...  We have two different issues mixed up in our discussion here. One
is about the typo in sentence 40.
See here: http://u.zelea.com:8080/v/w/Diff?b=2997&a=2995#L104
And the other is about the same typo but in sentence 20.
See here: http://u.zelea.com:8080/v/w/Diff?b=2997&a=2995#L70  ....

Please let us know, if you find any bugs!

Best,
Thomas