Optimization of BIH tree unit test.

- add test of find_point method
- add using of timer to test
- optimization of test class inner structure
Small change in unit test of BIH tree.

- add method for test of minimal, maximal and average depth.
BIH tree test of large mesh.

- add test of large mesh
- only geo file is stored in repository
Add printout of BIH tree structure.

- methods for print structure of nodes.
- add test of median, minimal and maximal count of elements in tree.
Fix of BIH tree construction.
Clean code of BIH tree.
Merge branch 'master' into DF_bih_tree