#19 Complete quoting for parameters in "configure.ac"

[Markus Elfring]

I recommend to be more explicit where macro expansion will not be required.
http://autogen.sourceforge.net/acquoting.html
http://www.gnu.org/software/autoconf/manual/m4/Quoting-Arguments.html

http://github.com/mm2/Little-CMS/blob/master/configure.ac