Adding additional check for blank language

Addresses #2366
Set lang to 'en' if it happens to be blank.

As a last-ditch fallback. Addresses #2366.
Fixing issue with RSS page header
Changed the robots index, follow columns to null by default
fix module checking role
separate files and file folders for each sites
separate for each sites in controller
files for each sites in wysiwyg
add api module
separate pages for each sites
separate comments for each sites
separate widget instances and widget areas for each sites
separate navigation for each sites
separate redirects module
separate user management for each sites
Merge branch '2.2/master' of git://github.com/pyrocms/pyrocms into develop

Conflicts:
	system/cms/modules/pages/details.php
Merge branch 'develop'

Conflicts:
	system/cms/migrations/125_Add_robots_meta_tag.php