lib: tree: Initial AVL tree commit

Signed-off-by: Bart Kuivenhoven<bemkuivenhoven@gmail.com>
lib: tree: Reorganise the tree api a little

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>
lib: tree: Move files into easy kernel positions

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>
lib: tree: Add polymorphism to ... C?!?!

Yep, aparently it can be done though some crazy function pointers.

Aw, come on! They're not that crazy!

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>
lib: tree: Add comments

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>
lib: tree: Add node count

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>
Merge branch 'master' of git://git.orion-os.eu/pub/avl into testing

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>

Conflicts:
	.gitignore