Added implementation for r_set_remove() according to documentation in set.h header
Fixup: member accessing
Fix: The hashtable should calculate the hash on its own
Fix: The hashtable should calculate the hash
Fix: The hashtable calculates the hash
Merge pull request #184 from matthiasbeyer/implement-r_set_remove

Added implementation for r_set_remove()
Added implementation for r_set_contains()
Merge pull request #181 from matthiasbeyer/implement-r_set_contains

Added implementation for r_set_contains()
Fix: Additional indent = 2
Fix: run astyle on avl/common.c
Added testing file for AVL implementation
Added allocation test for avl test
Added test for testing allocation and deleting for AVL
Added test for adding data to the avl tree
Added test for adding and destroying afterwards
Added test for adding multiple elements
Added test for adding multiple and destroying AVL afterwards
Added test for colliding inserts
Added test for finding a single element
Added test for finding multiple elements