SRCS and DVDREAD_SRCS depend on version.h; fixes parallel build.
Explanation: "[regularly] version.h gets built immediately because
it's the first target. However if you have multiple jobs
(-j3 or whatever), make will also begin building the .c files
without waiting for version.h to be built. This causes a race condition
if any .c file including config.h or version.h is built before version.h
Patch by Dan Nicholson: dbn.lists gmail com.