fix(server): Fix IE9 not showing any content.

* JSON responses were being sent with a content type of `utf8` instead of `utf-8`. `utf8` is invalid and IE would not parse the JSON. This resulted in neither config nor translations being loaded.

fixes #1095
refactor(client): Replace modernizr with html5shiv and a short test for js and touch screen.

fixes #1021
fix(build): Exclude env-test.js from the copyright check, it has its own from the Modernizr project.
fix(email): don't escape template strings with smart quotes
fix(email): generated templates should escape email and link variables
chore(docs): Add documentation on how email templates work.
fix(build): Remove Sync browser pages from distribution build
fix(tests): Fixed a regex typo in the reset password tests
Update CONTRIBUTING.md with git commit guidelines

Avoid the problem in #1123.
Merge pull request #1122 from mozilla/issue-988-remove-sync-pages

fix(build): Remove Sync browser pages from distribution build
Merge pull request #1124 from mozilla/issue-1058-fix-regex-in-test

fix(tests): Fixed a regex typo in the reset password tests
fix(emails): no need to HTML escape text based emails
chore(server): Move `env-test.js` into `vendor` since it is kind of sort of an external script.
Merge pull request #1096 from mozilla/issue-1021-into-antiquity

refactor(client): Replace modernizr with html5shiv and a short test for js and touch screen.
fix(client): Fix the styling on outdated browsers.

* Show the "browse happy" link to IE < 9
* Make the firefox logo look respectable on IE < 9

fixes #999
fixes #1014
fixes #1098
issue #1095
fix(client): Disable IE9 support until we get IE9's CORS situation situated.

fixes #1126
fix(client): Fix form validation on browsers that do not have HTML5 form field validation.

* IE < 10 do not have native form field validation. Validation must be done manually.
* To form.js, added validatePassword and validateInput.
* validatePassword validates passwords
* validateInput only checks if an input field is required on browsers without HTML5 validation. On other browsers, HTML5 validation will take effect.

fixes #1113
fixes #185
fix(marketing): add breakpoints for marketing snippet
Merge pull request #1111 from mozilla/issue-1054-smart-quote

fix(email): properly escape smart quotes

This looks good! Thanks @zaach!
Merge pull request #1097 from mozilla/issue-1095-ie9-blank

fix(server): `utf8` is not a valid content-type, `utf-8` is.