Make corrections after w3c validation & housecleaning

Issue #39

**Validation error corrections**
- Remove extra quotation mark in line 53
- Move lang="en-us" from html to body tag
- Close <meta http-equiv="X-UA-Compatible" content="IE=edge" /> differently -- FAIL
- Change closing bracket on html tag -- FAIL (not sure what the problem is here)

**Housecleaning**
- Change browsehappy message to make it a little more friendly
- Uncomment plugins.js
- Cleanup head tag some more