Add missing .php extension to group request membership template.
In Recent Blog Posts widget, do not assume what the site directory is.

Use native BP function - bp_blogs_directory_permalink() - to output the
correct site directory link.

Props @christianwach.  Fixes #153.
Merge remote-tracking branch 'remotes/upstream/master'

Conflicts:
	engine/includes/buddypress/bp-widgets.php