A collection of high performance c-string transformations, frequently 2x faster
than standard implementations.

including

    * base64, standard
    * base64, web/url safe, with configurable alphabet
    * base85 (good for http cookies)
    * base16 (hex)
    * base2 (ascii binary)
    * url escaping
    * javascript string escaping
    * fast number to string conversion, 4-22x faster than sprintf!
    * fast ascii upper/lower case conversion, 2-66x faster than stdlib!