Added CheckContext
Refactored things to use CheckContext
Removed old tokenizer
Added tests for check context
Changed indentation check to show the usage

It still doesn't work in terms of doing the actual job. Frankly, it
didn't have any chance to work even before the refactor.
Changed open tag check to work with new tokenizer
Merge branch 'master' into context
Merge pull request #23 from HippoPHP/context

Introducing context