Added implementation for ht_init()
Added functions to appropriate types for avl
Added functions to appropriate types for ll
Added functions to appropriate type for ht
Added linkedlist documentation group
Added license header to ht.h
Added ht.h to hashtable documentation group
Added utilities to utilities documentation group
Applied astyle on macros.h
Fixup: linkedlist group description
Added information that this member is static
Added information that this member is static
Merge pull request #80 from matthiasbeyer/implement-ht_init

Added implementation for ht_init()
Merge pull request #83 from matthiasbeyer/apply-astyle_on_macros

Applied astyle on macros.h
Merge pull request #84 from matthiasbeyer/add-documentation_groups

Add documentation groups
Merge pull request #85 from matthiasbeyer/add-grouping_documentation

Add grouping documentation
We should use the hash to identify the element to delete
Fix: Missing parentheses

These missing parnetheses could cause compiler errors or undefined
behavour, we want to avoid this.
Added ll helper for checking if a ll is empty

This patch adds a helper function for the linked list implementation to
check if the linked list is empty.
Added helper func for swapping two avl_el objs

This function is ugly and a hack, but should work like a charm and
really fast, too.