ANN: gtkmathview 0.7.3

Hi everybody,

This is a maintenance release that fixes the configure script,
gtkmathview's dependencies and a few delicate points in the source code
so that the component can be compiled in MacOSX and Win32 as well.

For building under MacOSX please see the README.MacOSX file in the
distribution. Similar documentation for Win32 is soon to come, in the
meantime J.M. Maurer says that "any recent mingw/msys with pkgconfig and
libxml2/libxslt installed should work".

Very special thanks to the AbiWord developers Hubert Figuere, Francis
James Franklin, Jean Marc Maurer, Robert Staudinger who have provided
valuable feedback and patches and made this release, which is the first
that officially compiles on three different architectures, possible.

Of course the work is not finished, and I'd like to see these new
platforms to support more than just the AbiMathView plugin (the SVG
backend already works under MacOSX, and chances are that it works under
Win32 too, but haven't tested).

Enjoy,
--luca