They are nearly the same as initially, except that now they include an
intermediate stamp header which will be generated by the build system.
The only 2 enums which don't need these includes (and are not versioned)
are libgimp/gimpenums.c and libgimpthumb/gimpthumb-enums.c.
We check them into git, so this makes it easier to keep them in
sync when using a separate build directory.
Case in point -- this commit also syncs a few enum files that went
out-of-sync with their headers.