Changes:
- You can now change the type of invokes to be run!
  All triggerable blocks can now have whatever invoke they want,
  instead of a fixed one (except the script block!).
  
  For example, the Clock-Block has 3 invokes now: Tick, Start and Stop
  All of these can be any of the following:
   - None
   - Block Trigger
   - Script File
   - Command
   - (more to be made available!)
  
  The invoke system is *very* powerful now, so be careful.
  Crashing the game just got over 9000% easier!

- Added/Finished the Relay-Block and its GUI.
  The Relay-Block can execute a set (of any size) of invokes when triggered.

Changes (internal):
- Gave QADButton's the possibility to have a Icon.

Fixes:
- Small fixes.