Limit main loop post types

Simplify results formatting.
Improve search results for pages
Allow Docs into main results stream

Add related search links to sidebar.
Simplify search results

Use BP widgets for member and group results. Requires change to member
widget: https://buddypress.trac.wordpress.org/ticket/5953
Remove old code
Update site search pre get post filter
Add accessibility styles for screen reader text

bump version number
Group narrative migration helper file

Creates new taxonomy terms
Merge branch 'search-rework' into 2.x

Simplifies search page
Generate fresh style sheets