Initial implementation object pool
Added getter/setter for GrowthPolicy
Changed offset type to size_t
Fixed check to ensure grow() always grows the pool with at least 1 more element
Moved actual capacity increase to seperate method, to avoid recursive mutexes
Moved GrowthPolicy enum outside of ObjectPool scope
Made docu more accurate
Changed parameter type of yield() to pointer, since delete() also receives one
Implemented base class PoolableObject:

Objects inheriting PoolableObject will have their memory managed by
an ObjectPool.
Changed faulty delete to free()
Moved ctor/dtor implementation to declaration
Made PoolObject friend of ObjectPool and turned all of ObjectPool's members private
Sorted member declarations
Turned Organism into a poolable object