Don't send up all_checked checkbox IDs upto server on onselect event.

- Made changes to JS method to not send up all_checked checkboxes on onselect event, this was causing JS error when there were lots of nodes in the tree, as a result of that transaction was not being sent upto server. Made changes to set/save C&U collection based upon checkbox that was changed and sent up. Removed code that was expecting all_checked checkboxes to come in with JS transaction.
- Changed code to only call Metric::Targets.perf_capture_always if any of the "Collect for All XXX" checkboxes values were changed and only for the one that's value was changed.
- Renamed set_perf_collection_object_list method to perf_capture_enabled_host_ids= changed it's caller to only send up list of host ids marked for collection for a cluster. Removed querying for hosts in controller.
- Removed code that was setting @temp[:cl_recs], it was not required to store Cluster Objects in @temp.
- Removed comment that no longer applies to the code.
- Added spec tests for perf_capture_enabled_host_ids= method to make sure it set/unsets performance capture on cluster and it's hosts.

https://bugzilla.redhat.com/show_bug.cgi?id=1153047
https://bugzilla.redhat.com/show_bug.cgi?id=1145799
Merge pull request #1044 from h-kataria/c&u_checkboxes_fix

Don't send up all_checked checkbox IDs upto server on onselect event.