Added implementation for ht_find()
Renamed function: avl_add() -> avl_insert()
Merge pull request #162 from matthiasbeyer/fix-insertion_func_naming

Renamed function: avl_add() -> avl_insert()
Merge pull request #160 from matthiasbeyer/implement-ht_find

Added implementation for ht_find()
Added debug print helper for linkedlist
Added debug printing for ll_destroy()
Added debug printing for ll_insert()
Added debug printing for ll_delete()
Merge pull request #152 from matthiasbeyer/add-debug_printing_ll

Add debug printing for ll
Reimplement adl_add