Seems to work on windows now

not everything works yet, but I've identified the main issues. Still
TODO: handle missing OMP libraries gracefully
Added olivetti faces data set. It required adding netpbmfile.py a bsd licensed pgm file reader from Christoph Gohlke, which doesn't seem to have a spearate installer. Also modified image_show to assume by default that array ordering is python instead of fortran. Modified brendan_faces demo to explicilty force fortran ordering. Notified Teo of change.
Merge branch 'devel' of https://github.com/SheffieldML/GPy into devel
Updated sympy code, multioutput grad checks pass apart from wrt X. Similar problems with prediction as to sinc covariance, needs investigation.
docstrinfs in kern.py
merged dimen reduction
parameter object done, printing fixed
indexing fixed, some equality testing
warning messages optional for re-constraining
more testing