[BUGFIX] Fixed NPE in TempPotionEffect

* Error: http://pastebin.com/nCYEudHr
[BUGFIX] Fixed error in Task #40 - Bloodbending

* Fixed error in bloodbending where targetentity somehow is in a
different world (probably by command) and that ends up causing errors
[BUGFIX] Fixed NPE in IceSpike

* Error:
http://www.projectkorra.com/threads/errorstacks-cause-pastebin-deletes.361/#post-3089
[BUGFIX] Fixed Task #23 - Combustion

* Error:
http://www.projectkorra.com/threads/errorstacks-cause-pastebin-deletes.361/#post-3090
[BUGFIX] Fixed NumberFormatExeception in Commands

* Caused by people misusing /b c thinking it is /b ch therefore
generation a NumberFormatExeception when they try pass an element as a
slot
Merge pull request #27 from jacklin213/bugfix

[BUGFIX] Fixed NPE in TempPotionEffect, Task #40 Error - Bloodbending, Task #23 NPE - IceSpike Error - Combustion, NumberFormatException - Commands