Fixed some bugs in regular convertor. Unit tests.

- Fixed and refactorized code to regular convertor.
- Added new operators e.g. <<,==,< and others.

!!! New project for unit tests was created. !!!

(The UnitTest project was created next to RegularConveror
project and includes are made by relative paths.)

Added tests:
- FA (Finite automata) concatenation
- FA alternation
- FA iteration