[Cin] blds/bld_prepare.sh update

[Andrea paz]

Mat is right, I too wonder if we really need gtk2 or perl or xorg
fonts. I don't know how the titler and fonts management works in CinGG
though, so I left them. I used to need other things like cmake (now
maybe it's changed). The graphic libraries are probably partly
installed by the DE, but I think it is not bad to leave them: if arch
finds them already installed, it simply overwrites them without
redownloading them, so it is a matter of seconds. Also the various
...-utils, vainfo, clinfo etc are not needed at all, but could be
useful in case of problems, so I thought to leave them.
You can remove alsa-lib; libpulse and python, because they are
certainly automatically put in by DEs.

Out of curiosity: there is also a list of dependencies in the AUR
package, there are 32 of them. It can be found here:
https://aur.archlinux.org/packages/cinelerra-gg

I mean, like you, I'm not sure if it's better to have a minimal list
or to stay with an " excessive" one.