Fix the missing `_`
RP API bits

(cherry picked from commit 52ac54ce6ce2b724b4f42b41dd81fa6206acc65d)

Conflicts:
	apps/system/js/fxa_manager.js

(cherry picked from commit 040419c1b258eb8f86b5aa6c4e34209c45290cc6)
Logout

(cherry picked from commit 358d1f892e9eeba9d3b405f6eadbc79b4de1b60d)

Conflicts:
	apps/system/js/fxa_manager.js
	test_apps/test-fxa-client/index.html
	test_apps/test-fxa-client/js/app.js

(cherry picked from commit 027be8eb79f246dbbfe2097a7624df8f5d17305a)

Conflicts:
	apps/system/js/fxa_manager.js
	test_apps/test-fxa-client/index.html
	test_apps/test-fxa-client/js/app.js
Fix RP tests

(cherry picked from commit 72201b12995564aee6562eb28e5e6386924b2447)
(cherry picked from commit ca7623e04c6c71411e47914a2d22dfec1ae353f3)
Merge pull request #3 from ferjm/all-fxa-things

Adds logout and RP tests

Thanks! I'm going to open another PR against borjasalguero/gaia/fxa_proposal_complete as well.