Improvement/pattern tools

[Mwexim]

This pull request aims to improve pattern utilities by extending the parse marks with more functionality:

• Parse marks now are called 'marks' for short (to not make the methods too long)
• Strings are now the base components of parse marks and allow alphanumeric values.
• If no mark is given (like (:first choice|:second choice)), the stripped text representation of the ChoiceElement will be the mark. This means that a choice group :first [choice] won't have 'first [choice]' as parse mark, but 'first' (notice the space at the end is omitted).
• You can also use the ':' character in front of a group (like :(first|second)) to apply this behaviour to all elements of the group (except for the ones that still have a mark present: these will override this behaviour).
• A list of all parsed marks is now present in the ParseContext instead of a simple integer value.
  • You can still use getNumericMark() which will parse all strings as integers (with the correct base) and XOR them accordingly (basically the old behaviour)
  • You can use getSingleMark() to quickly get a mark.
  • You can use hasMark(String) to quickly check if a mark is present.

This will be very helpful for patterns that require multiple parse marks in different groups. In all other cases, you probably are better of using integer marks.

[Mwexim]

See this PR by the way to have a better context as of why these changes were made.