973784 - refactored dependency solving workflow for performance

Data in now cached between iterations of dep copying, and some
steps were optimized out of the workflow.
improvements based on review
Merge pull request #453 from pulp/mhrivnak-973784

973784 - refactored dependency solving workflow for performance
Raise all setup.py versions to 2.4.0.
Update to centralize the yum pulp-profile-update plugin in the handlers component
Merge branch 'master' into barnabycourt-refactor-packaging

Conflicts:
	devel/setup.py
	plugins/pulp_rpm/plugins/importers/yum/depsolve.py
	pulp_rpm/src/setup.py
Update for merge