- simplified background drawing (+added option to use jpeg/png image)
- better default clipping planes

while clicking on rotation/1:1 button in status bar)

- update gl2ps to 1.3.3

  buggy)
- small doc updates

  kernel-specific information
- better documentation of lists returned by extrusions

tests with jf

renamed offending blas bits in Chaco; let's see if it fixes the problem

- don't include Chaco by default: it screws up the blas/lapack interface