Improves shadow rendering and changes the overall depth of field approach.

* Adds that the focus point for the depth of field effect is adjusted according to the players block camera target (with a range of 500 possible blocks/units
* Fixes incorrect depth range for the DOF effect
* Reduces shadow map size
* Disables linear sampling for the depth buffer (when did I enable this??)
* Adjusts shadow map x,y,z range to allow much more (blocky) detail
* Fixes absurdly wrong shadow/light camera position
Fixes and tweaks various rendering related things.
Adds some minor rendering related fixes and tweaks.
Moves sky textures from Skysphere class to ShaderParametersSkysphere.
Fixes that the GUI animation FBOs didn't have an attached depth buffer (which caused blocks/block icons to be rendered incorrectly) and plopping at some points in the GUI. Maybe opacity animations can be implemented without using FBOs at all?
Introducing Holdings! Which so far only attempts to associate Spawnables with a Holding and then do stuff based on how many are attached to said holding.
- For each 10 normal GelCubes that come out of a single normal Portal (natural cap is 16 GelCubes) they'll nominate a queen who is also a Spawner :D
 - All Spawnables have a parent Spawner set (later can use to correctly cap mobs based on their exact origin Spawner)
- Temporarily comments out world spawning (easier to deal with counts purely from portals)
- Plenty of minor hacks/bugs still to fix
Introduced modified attribute (color) for queens, to enable better tracking of them.
Quick implementation of portals spawning Oreons - not the cleanest, but could be worse!
Fixes shader compile error when changing blur related settings.
Fixes applet - hopefully (missed lib jar name changes)
Tweaks default video settings.
Fix OpenGL errors.

Fixes MovingBlocks/Terasology#461.

The switch statement requires GLSL 1.3, and OS X doesn't support it, so
fake it with if-then-else statements.

The graphics card in my Macbook Pro doesn't support FBOType.NO_COLOR
either, and I suspect this applies to multiple Mac models.

Tested on a MacBookPro5,3, with OS X 10.8.2.
Add new "plants" module with a big pile of farm-style plants from @Metouto :-)
Fix for disabled sound mode - the audio manager now determines how to load sounds, so the NullAudioManager can load a NullSound instead of an OpenAL sound.
fixed a swim movement bug where the BulletCharacterMovementSystem sent a character into the sky if they hit a corner underwater
Changed the slope value on swim so that the player can slide up slopes underwater
Merge pull request #467 from sdab/integrate

A bux fix for issue #340
Fixed a bug in the railgun tool. TunnelAction now cancels the activate event if it end up destroying no blocks. I also increased its priority to HIGH so that PlaySoundAction is lower than it. The result is that an explosion sound will only play if the railgun actually destroys blocks
Pressing right arrow key in chat while in debug mode no longer fast-forwards time
Merge #468 from @sdab - railgun tweaks