bug#23179: 25.0.92; Restore `M-,' to continue etags search

[Eli Zaretskii]

> Date: Sun, 3 Apr 2016 20:32:17 +0200
> From: Anders Lindgren <andlind@gmail.com>
> Cc: Eli Zaretskii <eliz@gnu.org>, 23179@debbugs.gnu.org
> 
> > Anders, can you see if this provides a solution to your problem?
> 
> I gave the code a test. It's a step in the right direction. However, I found 
> some problems with the approach

Are these problems grave enough that you'd prefer not to use such a
new command?