[BioC] Reading hundrets of .cel files and QC thereof

[Jeff Gentry]

> of .CEL files from NCBI GEO.  Take a look at GSE2109, which has 1400 samples 
> on the plus2 array, if I remember correctly.

FWIW I made an exprSet using GSE2109.  With 16GB of RAM I still was forced
to use just.gcrma() as I could not build it the long way (which was fine
for my purposes).