Add feature to match multiple regexes simultaneously

[SicroAtGit]

A RegEx ID number can then be specified for each RegEx, and in the event of a match, the RegEx ID number can be used to determine which RegEx has matched.

If there are multiple RegExes that match the same string and have been assigned different RegEx ID numbers, the RegEx ID number of the last matched RegEx is taken, i.e. the last matched RegEx added with the AddNfa() function.

Useful for building a lexer where different RegEx ID numbers can then be used for the different token types.