Debian package: Add changelog entry for new upstream snapshot
Debian package: Resync conkeror.desktop's MimeType with iceweasel's

Ignore application/vnd.mozilla.xul+xml though.

Closes: #746691
stackexchange.js: Update browser objects according to new format.

Changes "span" to "a".
stackexchange.js: Add fallthrough keybinds

Stack exchange now supports keyboard navigation.
Here we add fallthrough keybinds to avoid collision with the site's own keys.
The mode itself is still useful, because the site's key don't cover everything.
stackexchange.js: Exclude "review" and "users" path from URL regexp

None of the mode's features apply to these subpaths, so we exclude them.
Also adds emacs.stackexchange.com site (and others).