Fixed #612

* Chests send contents updates to client
Fixed #627

- Attack() is now called from cAggressive instead of cMonster
* Monsters can no longer attack through walls
* Should fix last remnants of player damage after teleporting (that both
STR and bearbin contributed fixes to :P)
Fixed #190

+ Hoppers now collect pickups above them
Improved pressure plates

+ Two (or more) pressure plates can be triggered at the same time
* Fixed issues caused by pressure plates not being in the sources list
Simplified Attack() tracing
Made player jump reset less ambiguous
Changed inheritance a bit

* cBlockEntityWithItems now inherits from cBlockEntityWindowOwner
Removed some unneeded BroadcastWholeWindow()s
Added more missing GetClassStatic()s
Fancy stuff with constant references
Added proper debug messages
Exported cWorld::BroadcastParticleEffect.
Documented BroadcastParticleEffect
Merge pull request #677 from mc-server/BroadcastParticleEffect

Broadcast particle effect
Removed debug messages again
Fixed typographical error
Merge pull request #664 from mc-server/generalfixes

General fixes
Add Fence Gate to Redstone Simulator
Add more Sounds to Redstone Simulator
Debuggers: Added a WebAdmin StressTest page.

This page reloads content from the WebAdmin as fast as possible.