Fix un-encoded tab character in error message.

After running phpcs on my large codebase this is the only thing that
broke it when saving the output as json.
Fixing namespaces being incorrectly detected as constants.
Merge branch 'true-namespace' of https://github.com/renan/PHP_CodeSniffer
Made uppercase sniff behave the same as lower + unit test fixes + changelog
Changed single quotes to double as single causes issues for some users
Merge branch 'bug/tab_json' of https://github.com/blainesch/PHP_CodeSniffer
Updated changelog
Merge branch 'master' of https://github.com/squizlabs/PHP_CodeSniffer
Added a thank you