(svn r20960) -Add: Allow setting 'minimal compatible version' via Action14. (planetmaker)

Note: Setting 'VRSN' also sets 'MINV' resulting in the Grf being only compatible to the same version. Set 'MINV' after 'VRSN' if your Grf is compatible to older versions.

src/newgrf_config.cpp

@@ -40,6 +40,7 @@ GRFConfig::GRFConfig(const GRFConfig &config) :
 	ZeroedMemoryAllocator(),
 	ident(config.ident),
 	version(config.version),
+	min_loadable_version(config.min_loadable_version),
 	flags(config.flags & ~GCF_COPY),
 	status(config.status),
 	grf_bugs(config.grf_bugs),