FEAT: add support for not, > and < constraints at the parser level.
BUG: fix Version hashing.
ENH: add >, < and != support in Requirement class.
ENH: improve repr of requirements with strict operations
ENH: add support for glob in requirement string.
BUG: add hashing protocol to constraints for python 3.x.
BUG: fix typo in glob version handling.

Fix to ensure glob version don't have pre-release/build parts
REF: extract out DecisionsSet and test it explicitely.
Merge branch 'add_strict_not_constraints'

Conflicts:
	depsolver/solver/core.py