add StreamTrans
add Attoparsec
IterX: clean up export list
IterX: add feed
IterX: add Status/cxtFailure

These give better support for parsing
add IterX.Parser and IterX.Unsafe
add IterX.Parser.Binary
Exception: export IException class
Parser: add drop
StreamTrans: add StreamTransM
IterX: add iterXToStreamTrans