Mods are now proper instances of a class, no more static foo

Mods are now properly instantiated, so we don't need all the static foo anymore. Moved locking & some logging into prepare- & finishImport.

Other minor changes:
* Proper indentation for all remaining mods.
* A force re-sync now ignores the locking flag. This can still be iffy, if a client accesses WordPress at the same time and a sync is indeed already in progress. On the other hand it clears stuck locks, which could happen right now. I guess eventually the syncing process should be running in the background and the current auto-sync should only be a fallback for people that can't setup a cron-job or such.

Note: I'm sorry I didn't realize you kept hacking on it yesterday and I've replayed a bit of history as you can see in the commit log. If I remember correctly though, this gets handled by git just fine if you merge. Should you have a problem with it, let me know and I'll just rewrite the git-history on my fork.