Fix responses of aborted xhr requests when user closes dialog or browses away from RP.

* Add an abort method to the XHR object.
* Keep track of all outstanding XHR requests. In the window.onbeforeunload handler, abort all outstanding requests.
** errors no longer logged on the KPIs when the user closes the dialog
** onlogout no longer called in the communication_iframe for aborted XHR requests
** onlogout called in the communication_iframe for all other XHR errors.

FWIW - changes to micrajax were pushed to origin repo - https://github.com/stomlinson/micrajax, https://github.com/stomlinson/micrajax/commit/2364453e387b914d556c53de8ab01188e067146f

fixes #2423
fixes #3618
fixes #3619
update incorrect test label
While pondering an upgrade of mysql from 5.1.x to 5.6.x, it occurred to me
that we should know more about versions of linux, mysql, and phantomjs that we
use with travis, so this will dump that information for future
reference. Travis uses Ubuntu so /etc/lsb-release will be there, but it checks
first if it is there.
Use low level dom event binding functions to bind the beforeunload handler to window.
Merge pull request #3620 from mozilla/issues_2423_3618_xhr_abort_unload

Fix responses of aborted xhr requests when user closes dialog or browses away from RP.
Fix the lockdown error with i18n-abide

fixes #3639
Merge pull request #3626 from jrgm/travis-dump-more-versions

record linux, mysql, and phantomjs versions on each travis run

R+!!
Merge pull request #3640 from mozilla/issue_3639-lockdown-error

Fix the lockdown error with i18n-abide

fixes #3639.
Override .form_selection a font size. Fixes Issue #3634
Merge pull request #3643 from mozilla/issue-3634-tospp-font-size

Override .form_selection a font size. Fixes Issue #3634

Thanks @ozten. r+.