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.
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.