Reset @display when viewing drift history screen.

- Added change to reset @display when viewwing drift history screen to fix an issue where @display was still being set to vms/storages etc after clicking on links to relationships from host summary screen and then clicking on Drift History link from listnav on left side it was trying to render incorrect partial due to @display being set incorrectly. Drift History link from right side of the summary screen was working fine because going to summary screen resets @display back to "main"

- Added spec test to make sure @display gets reset by drift_history method.

https://bugzilla.redhat.com/show_bug.cgi?id=1123144
https://bugzilla.redhat.com/show_bug.cgi?id=1126085
replaced chart fieldsets with divs; added HRs where needed

https://bugzilla.redhat.com/show_bug.cgi?id=1124609
Added code to show list of domain overrides for instances.

- Added list of Domain overrides by priority, items in the list are clickable links to a domain containing instance override.
(cherry picked from commit d15b7b6)
Moved instance related code from get_node_info to a new method.

- Moved instance related code from get_node_info to a new method "get_instance_node_info"
- Added spec tests for the new method "get_instance_node_info"
(cherry picked from commit 0dc3f14)
Made further changes to list of overrides on instance summary.

- Changed links in the list to go to an Instance object in the domain that was clicked on. When a domain in the list is clicked, open parent nodes of an instance in the tree.
- Added helper method to determine domian name to be displayed on the list.
- Changed view to not create a link for the Domain that user is currently on in list of overrides.
(cherry picked from commit 0701888)
Changes to show list of overrides on method/class summary.

- Added support to show list of overrides for Automate class and method on their respective summary screens. Moved code that sets domain overrides for instance/class/method records into one common method.
- Moved common view code to display list of overrides for class/instance/method into a common haml view. List of overrides is only displayed where any overrides exist accross domains. Rows in the list have a link to go to the respective object in the domain that is being clicked on, there is no link on the row with a domain that user is currently on.
- Fixed existing spec test to call correct method ot test get_instance_node_info and added spec tests for get_method_node_info & get_class_node_info methods.
Converted image-based form buttons to Patternfly btn class buttons
Removed validation for group existence from controller

This validation is already being done by model, removed it from controller this was causing 2 flash messages on the screen.

https://bugzilla.redhat.com/show_bug.cgi?id=1092381
converted tabs to spaces, aligned hash rockets, adjusted formatting

Issue #1491
Some further tweaks to the text/titles.

- Use model method domain to determine record's domain name.
- Fixed spec tests, added domain key to Class/Instance/Method objects.
Exclude the undesired artifacts from running assets precompilation.

This is required due to #279.

We should find a better way of doing this as part of the packaging process.
Merge pull request #341 from jrafanie/exclude_undesired_artifacts_from_running_precompile_assets

Exclude the undesired artifacts from running assets precompilation.
Merge pull request #317 from h-kataria/ae_display_list_of_overrides_accross_domains

Added support to display list of overrides for Class/Instance/Method objects across domains
Merge pull request #322 from epwinchell/patternfly_formbuttons_1

Initial conversion of image-based form buttons to Patternfly btn class buttons
Merge pull request #338 from h-kataria/duplicate_flash_msg_on_group_add

Removed validation for group existence from controller
Merge pull request #335 from epwinchell/c_and_u_styling_fix

replaced chart fieldsets with divs; added HRs where needed
Merge pull request #329 from h-kataria/reset_display_instance_variable_when_viewing_drift_history

Reset @display when viewing drift history screen.