The current migration process for OOo user interface (e.g. toolbars,
menu bar) changes is very limited. User changes are only migrated if
there are no changes in a new version for that special ui element.
This enhancement tries to merge changes from users to a new version.
The merging process works only non-destructive which means that it
only adds entries. This assures that users don't have to make
interactive choices on conflicts.