A bunch of minor tweaks and optimizations to improve AdRotate.

Changelog:

[change] Variable height for ad blocks
[change] Variable height for ads in blocks
[change] New installer (New installs only)
[change] Tweaks to upgrade script (Upgrades from 3.7.2 and older only)
[change] Cleaner debug information for time schedules
[change] Time notation when creating ads now uses WordPress dictated times
[fix] Time notation for schedules, now uses only WordPress dictated times

Nothing too fancy, but important changes none the less.
The time notation should now be consistent everywhere and match up to what time WordPress thinks it is. This will make schedules and such work more reliable. Auto height for blocks obviously brings back the flexible height for blocks for those that have uneven adverts in blocks. The width can *not* use ‘auto’. If that would be allowed the block grid keeps screwing up in several browsers. So that remains fixed width.

Translation files have been updated and have several new or changed lines. So translations need updating.

Beta3 users. Some fixes and changes are not in your beta. So yes, you need to update too.