Add option Default Group for Users in LDAP authentication UI.

When Default Group for Users is enabled in Configure - Configuration - Authentication,
this default group can be used for all ldap users who use LDAP for authentication only,
for example, when an LDAP server does not have memberof attribute for groups.

https://bugzilla.redhat.com/show_bug.cgi?id=1060207
Add test cases for User. authenticate_ldap.

https://bugzilla.redhat.com/show_bug.cgi?id=1060207
Support Default Group for Users with LDAP authentication.

When Default Group for Users is enabled in Configure - Configuration - Authentication,
this default group can be used for all ldap users who use LDAP for authentication only,
for example, when an LDAP server does not have memberof attribute for groups.

https://bugzilla.redhat.com/show_bug.cgi?id=1060207
Fixed show/hide of ldap_default_group_div & updated pull-down choices.

- Fixed show/hide of ldap_default_group_div
- Changed 'Default Group for Users' pull-down choice <Choose> to <No Default Group>

https://bugzilla.redhat.com/show_bug.cgi?id=1060207
Fix and cleanup miqButtons javascript.
Fix multiple miqButtons invocations.
Move left_cell_bottom level up to prevent duplicit DOM ids.
Fixed feature id passed to assert_privileges call.

- Fixed feature id passed to assert_privileges call.
- Added code to only build trees that logged in user has access to, after catalog was added/saved for a limited user, right_cell_replace was not finishing loading because it wasn't able to replace the tree partials that weren't even there.
- Added dictionary lookup in flash message call to show correct title in flash message when Catalog is added/edited.

https://bugzilla.redhat.com/show_bug.cgi?id=1159421
https://bugzilla.redhat.com/show_bug.cgi?id=1161271
Merge pull request #778 from lfu/default_group_for_ldap_users_1060207

Support Default Group for Users with LDAP authentication.
Merge pull request #1077 from martinpovolny/miq_buttons

miqButtons fixes
Merge pull request #1081 from h-kataria/catalog_add_edit_fix

Fixed feature id passed to assert_privileges call.