Apply BSD license
Added initial build configuration

Project is separated into library libtagtree.so and client tagtree-cli
that uses it.
Project organization:
* source files are placed in src/
* header files are placed in include/
** headers with public library api are placed in include/tagtree
* built executable and library are placed into bin/
Ignoring files from build path thourgh .gitignore
Cosmetic changes in .gitignore file