[PATCH] emacs: Use a single buffer invisibility spec to fix quadratic search cost.

[David Bremner]

On Tue,  8 Nov 2011 21:55:28 -0500, Austin Clements <amdragon at MIT.EDU> wrote:
> Buffer redisplay requires traversing the buffer's invisibility spec
> This change switches to using a single element buffer invisibility
> spec.  To un-hide authors, instead of removing an entry from the
> invisibility spec, it simply removes the invisibility overlay from
> those authors.

Pushed to master.

d