Clean imports
Implement TreeApproximator

TreeApproximator is a simple K-Means-like approach to
make an approximation of a spatial distribution of points with a bunch
of positional vectors arranged into tree-like structure.

Each positional vector points into a center of clouds of vectors beneath
it in hierarchy.
Visualize TreeApproximator process and outcome

Draw2DMap was added to see how a tree is
stretched into the space.
Implement a stub for SampleHierrchy2Priority
Visualize more complex shape

Shape has four cluster and stretched across 3D space
Enhance visualizer

Defaults were changed and labels were removed.
Implement a tool to arrange texts into catalog

ArrangeText tool uses TreeApproximator to arrange a text's
collection into tree of folders.
Implement debug.time() method to count time that operation took
Add method to align nodes of the tree in one curve

Nodes each is rotated to place leaves close to their sisters.
Nothing much
Order nodes before enter into first one.
Add a view that shows an outcome of the align() method.
Nothing much
Nothing Much
Nothing Much
Add measure of time
Filter out low-frequency word
Sort a vector before add into cluster