Patch and test for Issue #313.
Added isFunctional method to KLabelConstant.
Update test.k
Update config.xml

Added <xml> tag and -- to issue#313 options
Update config.xml

Apparently checkstyle requires <xml> in the first line
Merge remote-tracking branch 'origin/master' into issue#313
Added attributes to xml declaration.
Update config.xml
Update config.xml

copyright
Merge pull request #315 from kframework/issue#313

Patch and test for Issue #313.