Make flash messages module more version-agnostic
Multimethod dispatch on version
* Move ver_pick to utils.version module (and rename to just 'pick')
* Add version based dispatch to flash module as example
* Add copy of distutils' LooseVersion (except a new style class) for
  version dispatch
* Add a memoized decorator
* Supersedes #786
Add is_a dispatch for LooseVersion
* List new versions in cfme.versions
Switch from copypasta'd memoize to functools32's lru_cache
Merge branch 'master' into origin-pr-786

Conflicts:
	cfme/configure/about.py
	cfme/infrastructure/pxe.py
	cfme/services/catalogs/catalog.py
	cfme/web_ui/__init__.py
	cfme/web_ui/flash.py
	cfme/web_ui/tabstrip.py
Merge branch 'master' into origin-pr-786

Conflicts:
	cfme/fixtures/pytest_selenium.py
Fix bad merge conflict resolution
Merge branch 'master' into origin-pr-786

Conflicts:
	cfme/services/catalogs/catalog.py
Take a screenshot, take 2
Merge pull request #862 from seandst/browser-none-screenshot

Take a screenshot, take 2
Catch exception when calculating current version
Fix references to ver_pick
Merge pull request #791 from weissjeffm/origin-pr-786

Multimethod dispatch on version
Initial docs rewrite
Some more work