This no longer explodes if running only one smoke test
cfme.web_ui.menu works with upstream nav

The upstream appliance (and its descendants) render the nav tree a little differently.
Fortunately, they still have the same element structure as the current version of CFME,
so it was possible to rework the menu nav to function on both.

In the process, I had to break some things apart, which resulted in what looks like a
pretty massive rewrite. The code could probably use some more comments/docs, but I'm
too close to it at the moment to be a good judge of what needs illumination.
nav menu tests
Add pxe provisioning
Added Host object model
Selects are "locate"able
Merge pull request #598 from seandst/locatable-selects

Selects are "locate"able
Added IPMI to host
Added power button support
Merge pull request #589 from psav/pxe_provision

Add pxe provisioning
Merge pull request #585 from seandst/upstream-compatible-nav

cfme.web_ui.menu works with upstream nav
Cleared up some multidispatch confusion

Also fixed up a str coersion error
Merge pull request #600 from seandst/no-nextitem-explodes

This no longer explodes if running only one smoke test
Merge pull request #597 from psav/host_model

Added Host object model