Added new CollisionData fields.
New functions:

• vector=xcl:ourNewVel()
  
• vector=xcl:theirNewVel()
  
• vector=xcl:ourOldAngularVel()
  
• vector=xcl:theirOldAngularVel()
  
• vector=xcl:hitSpeed()

Fixed getCollision E2helper description

Fixed vector leaks

Some functions was renamed, "attempt to index a nil value" error fixed, better "is" check, comparison operators

Fixed collision callback not working after reloading chip

Fixed some bugs

Fixed return types for xcl:entity(), xcl:speed() and xcl:delta()
Added xcl:ourEntity()

Added descriptions

Added descriptions