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
As the struct avl type is an embedded type, we shouldnt call free() on a ptr to it here
Added implementation for ht_destroy()