Uuencoding is notoriously badly specified. This implementation is compatible with the GNU Sharutils (http://www.gnu.org/software/sharutils/).
Further documentation and information can be found at http://www.haskell.org/haskellwiki/Library/Data_encoding.
Chop up a string in parts. Each string in the resulting list is prepended with the length according to the uuencode "specificiation".