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 think we should do this for a 2.0 release?
> Do what? drop 5.3? I am against for that assumption - we don't know when we will release 2.0. Maybe we will, maybe we won't ;)

That's what I meant by Fixer level min required version. Somehow, it should prevent trying to run 5.5 target fixers on top of 5.4 runtime. See my point? T_YIELD is 5.5 - OK, no problem. Fixers targetting T_YIELD are disabled to 5.4.