Bug fixes

I wanted to wait for more bug fixes or features until I release a new beta, but the situation seems to speak against that, because:
- it seems there are no actual bugs apart from the one that I fixed since beta1 (style options didn't work there, now they do)
- new features are unlikely for the near future because I'm going off to a one-month trip abroad.
- dopry reshuffles filefield again (and imagefield), so the future of filefield_image is unclear at this point.

Fixes since 1.1:

• #261693: Fix for 1.3 version of simplenews no longer implementing _simplenews_get_vid().

Possible fix for

New features:
- Refactored large parts of the code.
- Moved node locking to an earlier stage to more reliably detect node edit urls
and avoid unnecessary locking. This also allows user defined urls to lock
nodes for (no UI yet).
- by ptalindstrom: Display error message even when the same user tries to edit
its own locked node.
- by Frank Steiner: (Backport) Trying to regain lock when a lock has been
removed.

Changes since DRUPAL-6--2-1:

• Fixed node re-locking.

Changes since DRUPAL-6--2-0:

• #281584: Fixed editing locks not being released when navigating to a non-node url.
• #245685: Fixed endless page redirect if $base_url is set (ie. Drual is installed in a subdirectory).
• Fixed users being able to release arbitrary locks.