code review 4830051: acme: scrolling fixes + new home/end

acme: scrolling fixes + new home/end

Home and End previously navigated between
two different window locations: the top and
the bottom of the text.  Now they include a
third waypoint: the location where typing last
happened.  Thus, in a win window, typing
	ls -l
	<home>
scrolls to the beginning of the ls -l output.
A second <home> continues to the top of the file.

Makes Send scroll always, along with writes by
external programs to +Errors.

[rsc, 2011-08-02 02:32:33]

Hello r (cc: mccoyst),

I'd like you to review this change.

[r, 2011-08-02 03:29:34]

LGTM but i wonder if q1 wouldn't be a better idea. if i send a blob, q1 will put
me back at the start of the command's output. it's a small point and probably
unimportant and to be fair q0 is closer to the acme way.

[rsc, 2011-08-02 11:31:49]

Although it's named iq0, it behaves the way you describe.

[rsc, 2011-08-02 11:44:17]

*** Submitted as 00a8dbea691f ***

acme: scrolling fixes + new home/end

Home and End previously navigated between
two different window locations: the top and
the bottom of the text.  Now they include a
third waypoint: the location where typing last
happened.  Thus, in a win window, typing
	ls -l
	<home>
scrolls to the beginning of the ls -l output.
A second <home> continues to the top of the file.

Makes Send scroll always, along with writes by
external programs to +Errors.

R=r
CC=mccoyst
http://codereview.appspot.com/4830051

[mccoyst, 2011-08-02 14:32:56]

This works fantastically. Thanks, guys!