radix-tree: major cleanup
radix-tree: adapt defines to the new tree design
radix-tree: removed unused function, adjusted structure to the new tree design
radix-tree: fixed compiling issue
radix-tree: initial implementation of the new insert function

Lots of things are still missing.
radix-tree: fixed var naming
radix-tree: better debug message
radix-tree: implemented prefix_mismatch function
radix-tree: selectively instanciate the hash table
radix-tree: fixed compiling issues, implemented part of recursive_insert, added a check to node splitting needs
radix-tree: generalized code for every kind of node, not just the root
radix-tree: fix minor comparing issue

It should compare the adjusted key in order to fix the prefix mismatching.
radix-tree: improved code performance by adding an extra special case
radix-tree: added some utility macros
radix-tree: use the new macros to improve code legibility
radix-tree: added parent field in nodes
radix-tree: unset PARTIAL field when needed
radix-tree: properly split nodes when needed
radix-tree: remove const qualifier

This removes all compile messages.
radix-tree: fix indent issue