Added \w single case test and hard coded it
Added \W single case test and hard coded it
Added delimiter constants and the ability to set it via the constructor #1
Added the whitespace (\s) case and hard coded it to pass test
Added the non-whitespace (\S) case and hard coded it to pass test
Added digit and non-digit cases and hard coded to pass tests
Added zero or more times (*) case and hard coded to pass tests
Added one or more times (+) case and hard coded to pass tests
Added optional (?) case and hard coded to pass tests
Fixed some coding standards
Moved directory structure

Classes in the same namespace are better for test, because you can
overwrite any PHP function in a namespace.
Fixed wrong regex parser

* Created method assemble() to parse regular expression;
* Fixed literal() method;
* Fixed range() method;
* Fixed alternatives() method.