Better fallback support on Activity Admin for items with an unregistered type

The 'Type' dropdown on the activity edit screen is populated with types that
have been registered with bp_activity_set_action(). However, many legacy
plugins do not register their activity types correctly. This adds support
for editing these types of activity items.

Fixes #4786

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8085 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
POT, generated from r8085

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8086 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
BP_User_Query search_terms should match against user_login and user_nicename in addition to xprofile fields

This changeset changes the search_terms logic in BP_User_Query so that it
matches user_login and user_nicename in the core users table. Then, via filter,
the xprofile component amends the WHERE clause so that search_terms are matched
in the users table OR the xprofile data table.

Clauses have been refactored to subqueries rather than storing the matched
user IDs in PHP, for improved performance.

See #5155

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8087 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Match user_nicename and user_login in addition to xprofile fields in messages autocomplete

The AJAX handler bp_legacy_theme_ajax_messages_autocomplete_results() now uses
BP_User_Query and its search_terms parameter for matching users.

Fixes #5155

Props imath for an initial patch

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8088 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
POT, generated from r8088

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8089 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Improve strings used for <title> and header of directory pages

Our legacy method for creating directory titles involved concatenating the
component name into '% Directory', which did not work well in languages where
a term like 'Groups Directory' would be translated into a single word. In
addition, there was inconistency between the <title> element on directory pages
and the header element used in the page body.

This changeset introduces a 'directory_title' parameter to BP_Core_Component,
so that directories can register a fully localizable string as the title/
header for directories.

To avoid filter name conflicts, the filter names associated with the headers
on group and blog directory pages were changed to _directory_header. See r7942,

See #4726, #4630

Fixes #4631

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8090 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Merge branch 'master' into xprofile-types