Added a missing function for POutput.
Implemented parse_rtol_bit, which is necessary for zLib.
First implementation of zLib.
Moved the parse_rtol_bits implementation back to parsifal.

As this RTOL bit parsing madness is also present in ZLib structures, we might need it elsewhere.
There is also an incomplete version of rtol_bit_int and rtol_bit_bool in BasePTypes.
Rewrote zLib.ml to distinguish between raw DEFLATE (RFC 1951) and zLib (RFC 1950).

RFC1951 is correctly implemented.
zLib.ml lacks a real dump function, and some fields are not correctly taken into account for the moment.
The RFC1950 has been added to the repo.
Changed the way lists are displayed.
Implemented most of PNG chunks.
Updated AUTHORS.
Commented on PNG implementation.
Improved image_time chunk display.
Added a relevant exit code to test_png.
Updated TODO.
Implemented two more RR types: TXT and HINFO.
New tool to print DNS answers in IC2012-like format.
Improved TXT display (picodig was not very relevant on such RRs).
Improved AnswerOnly display to take more lines into account.

However, authority and additional records are discarded completely when using this mode.
New option for ic2012dns: filter-ip.
Bugfix: EMPTY message should only displayed on verbose mode.
New submission: CRISIS tutorial.
Some typos fixed.