Basic character class parsing
Correctly recognizes outer character classes containing subtracted classes (but doesn't parse those yet)
Bug fix: opening braces that represent literals don't increase the nesting anymore
Parsing a hyphen inside a character class if it represents a literal hyphen (and not a range boundary separator)
Fixed the directory hierarchy
Renamed "Circumflex" to "Caret"
Fixed naming
Ranges can be parsed
Range recognition uses token type checking instead of regex matching like before
Subtracted character classes are parsed correctly now, too.
Merge branch 'character-classes'