Prevent FirefoxOS showing a tooltip if the user entered a password but not a vpassword in the set password screen.

fixes #3502
Constrain tooltips to be displayed on the screen.
Fix the failing front end test when run in PhantomJS.
Merge pull request #3511 from mozilla/issue_3496-tooltips-off-screen

Constrain tooltips to be displayed on the screen.
Merge pull request #3513 from mozilla/issue_3502_set_password

Prevent FirefoxOS showing a tooltip if the user entered a password but not a vpassword in the set password screen.
Update for FirefoxOS

us_matchers is now a table, the key is the OS, the value is the string to search for.

Add the current FirefoxOS string

fixes #3373
Merge pull request #3523 from mozilla/issue_3373_b2g_ua_parser

Update coarse user agent parser for FirefoxOS