Comment 28 for bug 481541

(From update of attachment 161088)
I think it's good. Ben? Whaddayasay? I've asked for sr= but really I intend a
directed a=?.

Abridged version, or this entire bug in five sentences: This establishes yet
another pref for tuning what kind of tab gets focus when opened, or doesn't.
The argument is that tabs opened on left-click, such as the ones coming out of
bug 172962, would fain be focused when opened, while those tabs opened on
middle-click, such as the ones we've had for a long time now, would not.
Currently we use the extant middle-click pref and UI for both middle- and
left-click tabs. This patch uses a new left-click pref if it exists and falls
back to the middle-click pref, the one with a UI, if not. Yet another checkbox
in a future version of the Tabbed Browsing dialog is implied.

If we decide this is a good path to take, we should also consider renaming the
prefs before 1.0 to fit their true usage. The generically named
loadInBackground pref really applies only to middle-click tabs, which are fast
becoming only a subset of the tabbed world.