Mess does not require mame source to build anymore

[Emmanuel Kasper]

Hello Team ! ( again ...:)
While working today on the coypright files, with a bunch of

diff -qr mess-0.142/ mess-0.143/ | grep "Only in mess-0.143" | sed
's/^Only in //' | sed 's/: /\//' | xargs grep Copyright
etc ...

I noticed a lot of code from mame was added to mess. Looking on the mame
forums, I noticed that now mess releases include all the necessary code
to build without mame. I tried it "standalone" and it builds fine.

I don't know if and how it should change the way we package the apps.
At any case, I am nearly done with the 0.143 stuff, and we can soon
think of an upload.

Manu