Fixed zones tests; fixed QA contact error with metadata
DB Peeking speed up

Multiple changes here:
* Made cloud follow the STATS_TO_MATCH model from infrastructure
* Added in addition to UI based calls, added DB based calls for the
  following methods for providers; validate(), num_*() and
  _do_stats_match.
* get_server_roles, which is used in the server_roles fixture now has a
  DB companion, this uses the same logic as CFME to determine which
  roles are present in the UI.
* set_server_roles was modified to only navigate if the roles do not
  match, subsequently the entire fixture can be run without touching the
  UI assuming that the roles match.
* IPAppliance object now also has access to the server_configuration
  which is also cached and needs to be invalidated if any changes are
  made to the server configuration.
* PXE module received DB methods for many of its class exists() methods.
* By default all getters which have DB getting enabled, use DB by
  default and so certain tests have been modified to *NOT* use the DB if
  the intention of the test is to test the UI elements.
Merge pull request #1397 from psav/db_speed_up

DB Peeking speed up
Merge pull request #1419 from mfalesni/zone-fix

Fixed zones tests; fixed QA contact error with metadata
PRT now doesn't care about Exception at cleanup

...just keeps on trying
Merge pull request #1420 from psav/prt_stop_whining

PRT now doesn't care about Exception at cleanup
Print Error
Merge pull request #1421 from psav/prt_stop_whining

Print Error
Signal handler
Merge pull request #1422 from psav/signal_handler

Signal handler
Initial signals usage

Signals are now used to indicate that the server details and server
config have changed.
docs fixes, tracking down some weird errors
Merge branch 'docs-fix'
Merge pull request #1423 from psav/signals_methods

[WIP] - Initial signals usage
on_signal decorator
Fix import
Fixed get_first_floating_ip for OS
Merge pull request #1428 from psav/fix_ip_getter

Fixed get_first_floating_ip for OS
Merge pull request #1427 from psav/fix_ci_test

Fix import
Merge pull request #1425 from mfalesni/signaldecorator

on_signal decorator