doc: Remove obsolete gen-finalize-docs.cs tool
doc: Remove obsolete gen-finalize-docs.cs tool

It was used to automatically document the Finalize methods, which do not
exist anymore. We are now using the standard Dispose pattern, and the
Dispose methods only appear in a few places, so they can be documented
manually.

antoniusriha/gtk-sharp,orion75/gtk-sharp,Gankov/gtk-sharp,Gankov/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp,sillsdev/gtk-sharp,openmedicus/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,antoniusriha/gtk-sharp,antoniusriha/gtk-sharp,orion75/gtk-sharp,openmedicus/gtk-sharp,openmedicus/gtk-sharp,sillsdev/gtk-sharp,antoniusriha/gtk-sharp,antoniusriha/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,Gankov/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,akrisiun/gtk-sharp,sillsdev/gtk-sharp,akrisiun/gtk-sharp,sillsdev/gtk-sharp,Gankov/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,orion75/gtk-sharp,orion75/gtk-sharp