Look for doxygen
Fixed typo in main gitignore
Add gitignore for documentation
Ingore stamp files used for trackign targets
Add CMakeLists file for building the doxygen doc
Ultimately add documentation target to project

...by including the ./doc subdirectory
Merge pull request #70 from neithernut/add-build_env-doc

Add build env doc
Merge pull request #73 from neithernut/add-node_cnt

Add node cnt
Add declaration and stubs for rotations
Add declaration of node metadata regeneration func

The function declared in this commit will regenerate a node's metadata,
e.g. it's height and the node count.
Add implementation of left-rotation
Add implementation of right-rotation
Add implementation of regeneration function
Merge prequisited of left-rotation
Merge prequisites of right-rotation
Add space to comments in left-rotation
Add space to comments in right-rotation
Add space to comments on regen_metadata
Fix regeneration of height.
Add function for subtree rebalancing