* Adds model layer changes around HealthChecks
1. Makes a HealthCheck model fragment and uses it in ServiceInstances and
Nodes
2. Manually adds a relationship between a ServiceInstance and its
potential ServiceInstanceProxy
3. Misc changes related to the above such as an Exposed property on
MeshChecks, MeshChecks itself
* Add a potential temporary endpoint to distinguish ProxyServiceInstance
* Fix up Node search bar class
* Add search/sort/filter logic
* Fixup Service default sort key
* Add Healthcheck search/sort/filtering
* Tweak CSS add a default Type of 'Serf' when type is blank
* Fix up tests and new test support
* Add ability to search on Service/Node name depending on where you are
* Fixup CheckID search predicate
* Use computed for DataCollection to use caching
* Alpha sort the Type menu
* Temporary fix for new non-changing style Ember Proxys
* Only special case EventSource proxies
* ui: Add predicate, comparator and necessary files for the search/sort
* Implement search and sort for upstream instance list
* ui: Tweak CSS so its all part of the component
* Remove the old proxy test attribute
John Cowen