SETI's graphics app

[Guo Yixuan]

Hi,

I prepared seti's graphics binary in graphics branch [1]. It compiles 
and works as expected. To avoid forcing people to install X-related 
libraries, two flavors are presented.

Current packaging style:
1. Build seti with --enable-graphics, which generate 2 binaries
2. Put both into package boinc-app-seti-graphics, and put the 
no-graphics one in boinc-app-seti.
3. Mark boinc-app-seti and boinc-app-seti-graphics as in conflict with 
each other.

Problems:
If you upgrade to boinc-app-seti-graphics from boinc-app-seti, several 
prerm/postinst will start/stop boinc-client many times, and WUs are 
lost. Is there better way than declaring Conflicts?

Questions:
I wonder if --enable-graphics will introduce performance penalty to 
SETI. If there is, maybe a build-twice style is better.

[1] git://git.debian.org/git/pkg-boinc/boinc-app-seti.git

Cheers,

Guo Yixuan