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
Fixed the Taable and SplitTable classes

* Changed the XPATH expression and made the search for elements start from a
root element instead of from DOM root
* Renamed occurances of browser to sel in the tasks.py page
* Removed the is_displayed() method and replace occurances with
sel.is_displayed()
Small docs fix
Add helper func sel.value() - to ease access to text in input/select elements
Add flash.assert_message_contain() to be able to check only parts of flash messages
Added Host object model
Merge pull request #590 from psav/fix-table

WIP:Fixed the badness
Selects are "locate"able
Add server name test
Merge pull request #593 from psav/fix-docs

Small docs fix
Merge pull request #595 from jkrocil/flash-contain

Add flash.assert_message_contain()
Merge pull request #594 from jkrocil/sel-value

Add helper func sel.value()
Merge pull request #596 from jkrocil/test-server-name

Add server name test
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