Working on the new layout for the install page.
Added browser language detection and pulls in any matching language pack advert.

Added ajax loaded extension selection.

@todo language strings, responsive testing, maxmind/openbay setup pages and paid-banner location.
Added language strings to step 4 install page.
Added Maxmind set-up after the install.
Added OpenBay module setup from install page.

@todo language strings and move images to cloudfront.
Finished OpenBay module page on install confirmation page.
Added checks for iconv / mbstrings to install pages.
Merge branch 'master' into install-changes