[Squeak-VMdev] [vmdev] Updated unix with the latest changes needed by VMMaker32-7.5

[Rob W. <rwi...@at...>]

I wasn't able to compile internal or external this weekend, so I fixed
it per Tim's intructions.  I didn't see the commit emails get sent, so
here is what I did:

- added osExports.c based from the RiscOS version.  Added the exports
for the browser plugin functions.  Bert, you may want to verify that
this builds for you
- removed platform.exports
- changed squeak/platforms/unix/misc/util/mkMake to use
SQUEAK_BUILTIN_PLUGIN defines for internal plugins.  Removed reference
to platform.exports as a basename
- changed squeak/platforms/unix/plugins/Mpeg3Plugin/mkMakeRules to use
SQUEAK_BUILTIN_PLUGIN define for internal mode

I tested from a clean checkout and it all looks well.

cheers,
Rob