Removed \0x000c from WS

I have no idea why, but \0x000c introduces an error parsing for example ' c(1,2)' ('c' as the function identifier and a whitespace preceding it).
Merge pull request #64 from hoesler/patch-1

Removed \0x000c from WS
Added \u000C
Merge pull request #65 from hoesler/patch-1

Added \u000C
Merge branch 'master' of https://github.com/antlr/grammars-v4