Organizations and Locations mismatches

DONE
* disabled ability to edit location/organization on edit host
* no option for blank location/organization for new host. 
* disabled ability to unselect location/organization settings used by host
* highlighted in red location/organization settings used by host that are not selected
* added validation for location/organization to ensure no orphan settings (used by hosts, but not selected)
* list of mismatched hosts and details of mismatches
* fix all mismatches

TODO functionality
* Add option for "All Hostgroups, All Domains, etc"
* Advanced Settings - select hosts on edit organization/location

TODO UI items, @abenari
* Catch error on hosts_controller#update_multiple_organization if no organization is selected. When this is fixed, then mismatch_error will also be catched if Pessimistic is checked.
* Increase width of Assign Locations dialog window
* Decide on wording, styling for "Optimistic - Import on Mismatch   Pestimistic - Fail on Mismatch" located in hosts/_taxonomy_import_option.html.erb 
* Placement, style, and wording for button "Mismatches Report" locations/index.html.erb and organizations/index.html.erb
* Placement, style, and wording for button "Fix All Mismatches" on hosts/mismatches.html.erb
* Ajax waiting notification for long processes for /mismatches and /import_mismatches