Suggestion: Class to handle Strings

@sv3tli0

It could be done with autodetection, the class could check for mb_string (faster, but less supported encoding), iconv (slower, more supported encodings), intl (I think, it has multibyte routines too, but they are likely not well documented). If none exists, then fallback PHP implementation (by method) could be done. For every method the best possible way can be picked up automatically.