As we are building the gtkreftestprivate and reftest test libraries as
DLLs, we need to export the symbols in there so that things will link.
Decorate the symbols with G_MODULE_EXPORT for this purpose.
When connecting signal names, gtk-reftest now allows you to use a colon
in the signal handler name like so:
module:function_name
where module is a module loaded from the same directory (or the .libs
subdirectory for compatibility with uninstalled libtool) as the running
test and the function is resolved in that module. Of course, normal
function names work as before.