Use psutil to set process affinity (test_perf.py) + minor pylint-friendliness for ._ix
please test test_perf.py -- I have rebased against master and had to resolve conflicts

Cheers,

can you hook up to travis?
 hm -- I thought that pull requests should also be travis'ed for pandas regardless where they are coming from... meanwhile enabled travis for neurodebian/pandas
 I think you need to set the github hook up (then login to travis), then recommit it

see contributing.md !
 perfect....merge?

and fyi....built successfuly on the sparc (very slow......!)
 Would have been fine to abolish affinity completely in favor of psutil.
