[Debian-med-packaging] Bug#648762: Bug#648762: mira: Fix detection of libexpat

[Michael Terry]

Upstream is using the macro AX_LIB_EXPAT.  They need to generate their 
next tarball using a newer version of autoconf-archive, at least 
version 2011.03.17 [1], which includes a fix for this [2].  And then 
they need to make sure to switch to using EXPAT_LIBS instead of 
EXPAT_LDFLAGS (since the macro changed which variable it defines).

My patch is just a minimally-invasive workaround until they they do 
that.

[1] http://www.mail-archive.com/info-gnu%40gnu.org/msg01160.html
[2] http://savannah.gnu.org/patch/?7489