Fixed missing const modifier
Implemented ll_is_subset
Implemented ll_equal
Implemented avl_is_subset
Implemented ht_equal
Implemented r_set_equal
Added files to CMakeLists
Added ll_equal and ll_is_subset tests
Added avl_is_subset tests
Added ht_equal tests
Added r_set_equal tests
Changed the test config

This commit changes the hashf so that the hash as quite larger hashes.
This way the hashes are more randomly distributed which is great for testing.
Merge pull request #206 from matthiasbeyer/implement-r_set_equal

Implementation for r_set_equal()