Pause all env. sound that is out of distance to go easy on
SDL mixer, this will decrease mixing of 30 events to 2-4.
Implement enemy-style loot tables for map events

The new formatting for the loot property in map events is as follows:

```
item id # or 'currency', x, y, quantity, percentage chance
```

An item id of 0 is equal to 'currency'.

This change has the added benifit of allowing items to drop in stacks of
more than one (e.g. 5 Health Potions).
Lock the Action Bar when transforming

Closes #401
Allow buff powers to use post_power

An example usage of this is to have a passive "buff" that has an ON_HIT
trigger to untransform the hero.
Don't allow equipment changes when transformed
Made the local data prevail upon installed ones.

This should be the case when no custom game data folder has been set,
and should permit to run the engine without the need to install it,
at least on linux.

fixes flare-game issue 160.
Merge pull request #404 from Bertram25/master

Fix for flare-game 160
Merge pull request #398 from hean01/env_sound

Pause all env. sound that is out of distance to go easy on
Merge pull request #399 from dorkster/map_loot

Implement enemy-style loot tables for map events
Merge pull request #402 from dorkster/transform

Lock the Action Bar when transforming