Model-work for merging events and entries. Merges are non-destructive, except in as much as the originals are flagged 'Merged' which implies inactive. These means merges can be undone, and the originals can in theory be linked to.
Controller work for merges.

Also, improved the entry that gets added to merges.
Now using the annotate gem. Here are the rest of the annotated files. Oh, and the missed migrations.
Small cleanup.