Bug#888657: ladish and flowcanvas: upstream clarification

[Nedko Arnaudov]

Upstream wise, ladish was switched to internal copy of flowcanvas in
2012, in git commit 67cc9c9e05d47e6074167fc05c12ec87e8c0058e, available
in public git repositories ever since.

The removed external flowcanvas depencency is used by gladish gtk2
(debian mate?) frontend of ladishd. Both gladish and ladishd programs,
are part of the upstream ladish project.

* commit 67cc9c9e05d47e6074167fc05c12ec87e8c0058e
| Author: Nedko Arnaudov <nedko at arnaudov.name>
| Date:   Sat Apr 7 23:47:03 2012 +0300
|
|     embed flowcanvas-0.7.1