Allow for lexing raw character token

This is useful when needing lookahead (non-greedy operator, negated
character class, flags).
Do not use lists

conversion from queue to list and pattern matching on lists slows the VM
down. Remove this hotspot by keeping only queues.
Add benchmarks

Making elements `Serializable` is required for micro benchmarks but is
also a good idea in general to have.
Better support for finding all matches

Up to now, when using `findAllMatchIn` the start index was always 0
based, because we matched from a substring. Improve this part by not
creating substrings.
This has the nive side-effect of improving the eprformances by a factor
of 3.
Avoid endless loops

When the regular expression matches the empty string, only match it
once in the end of the string in `findAllMatchIn`.