* Fix bug discovered while running Hufflepdf on a PDF output from pdftk : magic keywords like `obj`, `stream` or `xref` can have spaces after them before the EOL
* Rewrite the parser using attoparsec instead of parsec (about 1.5x faster)
* Use strict ByteStrings instead of lazy ones for an additional gain in performance, simpler type interface (lazy ByteStrings are now used only for output because that's required by the ByteString Builder) and fewer import lines