feature(admin): Use elgg_view_menu to generate admin header
Merge pull request #7288 from PerJensen/admin_header_menu_new

fix(views): removes hard coded menu from admin header
perf(entities): preloads owners when drawing lists of entities/likes

When drawing lists of entities/likes with a variety of owners, many owners
end up being loaded one by one (inefficient). This adds a component that
walks the list and preloads all the owners into the cache in one shot.

Fixes #5949
Merge pull request #6975 from mrclay/5949_2

perf(entities): preloads owners when drawing lists of entities/likes