Bug 1071074 - Redirect remaining /firefox/channel/ pages from PHP to Bedrock

/mn/firefox/ is now redirected to /en-US/firefox/new/ as per the bug.
Merge pull request #337 from kyoshino/bug-1071074-firefox-redirect-mn

Bug 1071074 - Redirect remaining /firefox/channel/ pages from PHP to Bedrock
Fixing DNT redirect and adding test for it
Merge pull request #338 from retornam/fixdnt

Fixing DNT redirect and adding test for it
Fix test_dnt_redirect
Merge pull request #340 from jgmize/fix-test_dnt_redirect

Fix test_dnt_redirect
issue 339: xfailed not relevant for new design tests, added new tests

removed xfail for signup, now working as expected

removed images related tests

fixed locator and url_suffix
Attempt to fix test bustage by adding "Cookies" link
Merge pull request #344 from stephendonner/fix-footer

Attempt to fix test bustage by adding "Cookies" link
fix for the issue #345
Merge pull request #346 from stupchiy/fix_footer_links

fix for the issue #345