firefox: Update to 78.0

* Some dependency changes.
* Wayland and webcam may not work.

Changelog:  New

    The Protections Dashboard includes consolidated reports about
    tracking protection, data breaches, and password management.
    New features let you:

	Track how many breaches you窶况e resolved right from the
	dashboard

	See if any of your saved passwords may have been exposed
	in a data breach

    To view your dashboard, type about:protections into the address
    bar, or select 窶弃rotections Dashboard窶� from the main menu.

    Because we know people try to fix problems by reinstalling
    Firefox when a simple refresh is more likely to solve the issue,
    we窶况e added a Refresh button to the Uninstaller.

    With this release, your screen saver will no longer interrupt
    WebRTC calls on Firefox, making conference and video calling
    in Firefox better.

    We窶况e rolled out WebRender to Windows users with Intel GPUs,
    bringing improved graphics performance to an even larger
    audience.

    Firefox 78 is also our Extended Support Release (ESR), where
    the changes made over the course of the previous 10 releases
    will now roll out to our ESR users. Some of the highlights are:

	Kiosk mode

	Client certificates

	Service Worker and Push APIs are now enabled

	The Block Autoplay feature is enabled

	Picture-in-picture support

	View and manage web certificates in about:certificate

    Pocket recommendations, featuring some of the best stories on
    the web, will now appear on the Firefox new tab for 100% of
    our users in the UK. If you don窶冲 see them, you can turn on
    Pocket articles in your new tab, follow these steps.

Fixed

    Various security fixes.

    We fixed bugs in the search results quality composition and
    improved search result texts based on recommendations by our
    partners.

Changed

    The minimal system requirements on Linux have been updated.
    Firefox now needs GNU libc 2.17, libstdc++ 4.8.1 and GTK+ 3.14
    or newer versions.

    As part of our ongoing effort to deprecate obsolete cryptography,
    we have disabled all remaining DHE-based TLS ciphersuites by
    default.

	To mitigate web compatibility issues from disabling DHE-based
	TLS ciphersuites, Firefox 78 enables two more AES-GCM
	SHA2-based ciphersuites.

    We have disabled TLS 1.0 and TLS 1.1 to improve your website
    connections. Sites that don't support TLS version 1.2 will now
    show an error page.

    The context menu (accessed by right clicking on a tab) lets
    you undo multiple tab closings with a single click and places
    Close Tabs to the Right and Close Other Tabs in a submenu.

    A number of accessibility improvements have been made with this
    release.

	When using the JAWS screen reader, pressing the down arrow
	in an HTML input control with a datalist no longer incorrectly
	moves the cursor to the next element after the input control.

	Screen readers no longer severely lag or freeze when focusing
	the microphone/camera/screen sharing indicator.

	Large tables with thousands of rows now load much faster
	for screen reader users.

	Text input controls with custom styling now correctly show
	the focus outline when appropriate.

	Screen readers no longer sometimes incorrectly switch to
	document browsing mode unexpectedly when the user enters
	the main Developer Tools window.

	We reduced a number of animations such as tab hover, search
	bar expansion, and others to reduce motion for users with
	migraines and epilepsy.

Enterprise

    Enable support for client certificates stored on macOS and
    Windows by setting the experimental preference
    security.osclientcerts.autoload to true.

    New policies allow you to configure application handlers,
    disable picture in picture, and require a master password,
    which will be renamed to 窶湾rimary password窶� in future releases.

    More details in the Firefox for Enterprise 78 release notes

Security fixes:
Not available yet.


(ryoon)