Become a GHC build slave!

[Richard Giraud]

I believe that there is value in having multiple BuildBots for the same 
platform.  More value is provided when differences are maximized between 
BuildBots but there is value in having similar BuildBots (particularly, 
if the similar BuildBots are popular).

Even in the relatively monoculture world of Apple, there is a lot of 
variation:
- The G4 and Core chips are 32-bit and the G5, Core 2, and Core 2 Xeon 
chips are 64-bit.
- The G4 chips have some endianess instructions that are not present in 
the G5s.
- The G5 and Core chips may have 1 or 2 cores in them.
- The G5 and Core 2 Xeon chips may come in 1 or 2 CPU variations.
- The Core 2 Xeon chips will soon come in 2 or 4 core versions.
- The PPC chips support 2 major versions of Mac OS X (10.3 and 10.4).
- Third party libraries and applications can come from from:
   - Apple.
   - darwinports.
   - fink.
   - manually installation.
- The libraries may have multiple versions.

Creating a bunch of similar BuildBots will help improve coverage of 
these differences.

Wilson MacGyver wrote:
> You can see that here.
> 
> http://darcs.haskell.org:8010/
> 
> and it looks like Thomas Davie already has both OSX PPC and OSX intel 
> covered.
> there is no reason for multiple build-bot for the same platform is there?