[core] New cookies manager implementation based on a custom implementation. This is done because of following reasons:

* Rendering according to the excellent new RFC 6265 (rather than using a unique ad hoc format inconsistently relating to
  unrealistic, very old RFCs which everyone ignored). Uses URL encoding to represent non-ASCII by default, like many other languages' libraries
* Liberal parsing, incorporating many complaints about Cookie.py barfing on common cookie formats which can be reliably parsed (e.g. search
  'cookie'on the Python issue tracker)
* Well-documented code, with chapter and verse from RFCs (rather than arbitrary, undocumented decisions and huge tables of
  magic values, as you see in Cookie.py).
* Test coverage at 100%, with a much more comprehensive test suite
  than Cookie.py
* Single-source compatible with the following Python versions:
  2.6, 2.7, 3.2, 3.3 and PyPy (2.7).
* Cleaner, less surprising API
* Friendly to customization, extension, and reuse of its parts.

It also leaves out a few properties that aren't really necessary:
* Maintain backward compatibility with Cookie.py, which would mean inheriting its confusions and bugs
* Implement RFCs 2109 or 2965, which have always been ignored by almost everyone and are now obsolete as well
* Handle every conceivable output from terrible legacy apps, which is not possible to do without lots of silent data loss and corruption (the
  parser does try to be liberal as possible otherwise, though)
* Provide a means to store pickled Python objects in cookie values (that's a big security hole :) )

This module will also have some functions for post-scan session/user-roles analysis, and on-the-fly sessions analysis.
Updated to reflect changes in cookie implementation