Bug 27476: Implement about:torconnect captive portal within Tor Browser
- implements new about:torconnect page as tor-launcher replacement
- adds tor connection status to url bar and tweaks UX when not online
- adds new torconnect component to browser
- tor process management functionality remains implemented in tor-launcher through the TorProtocolService module
- the onion pattern from about:tor migrated to an .inc.xhtml file now used by both about:tor and about:torconnect
- various design tweaks and resusability fixes to onion pattern
- adds warning/error box to about:preferences#tor when not connected to tor
- explicitly allows about:torconnect URIs to ignore Resist Fingerprinting (RFP)
- various tweaks to info-pages.inc.css for about:torconnect (also affects other firefox info pages)
- auto connects if already connected successfully before (using the legacy prompt_at_startup pref)