And so remove the current year to ease maintenance and since it is not
strictly necessary.
Also remove individual copyright holders (where appropriate) and replace
the name with "The Geany contributors". The detailed authorship
information is still available in the GIT history.
Also remove copyright notice and author names from READMEs.
* Add GEANY_ prefix to enumerators.
* Use a discrete set of enumerators so the proxy doesn't have to
worry about flag bitmasks, which isn't required.
* Update documentation.
* Use the new enumerators in Geany.
* Improve debug output for bogus values a bit.
This demo proxy does not actually do anything useful. It simply loads
pseudo-plugins from an ini-style file. The point is that there will be a plugin
in the PM dialog for each ini. Each ini-plugin also causes a menu item to be
generated.
