LowercaseConstantsFixer - rewrite to handle new test cases

LowercaseConstantsFixer - rewrite to handle new test cases.
Resolves #793.

May not work on php 5.3 yet
I really wonder which situation is this that someone is using PHP 5.4 or 5.3 locally to format a PHP 5.5 that is going to be deployed. I mean, you are right. It is possible - I question first, whether it is likely; second, whether things are more complex for sake for flexibility.