Backporting "terminate if not responding" patches from 4.6 to 4.4.3

[Jayson King]

Greetings,
I posted a bug on Fedora's bugzilla with a backported patch to add the 
"terminate if not responding" dialog patches from the 4.6 beta to the 
latest stable 4.4.3. If it is considered worthwhile to have this 
capability in the latest stable version, then please use it.

https://bugzilla.redhat.com/show_bug.cgi?id=471197

The patch is for the "release" package so it touches configure.ac and 
Makefile.in files, which you probably don't want. (configure.ac.in isn't 
in the release package so it isn't in the patch, but it needs a change 
too). I'll post a more suitable patch here.

Jayson