BF: don't use dtype with ones/zeros_like

Use ones/zeros(arr.shape, dtype) instead - for compatibility with older
numpy - at least numpy 1.5.0 does not have this.
RF: bump minimum numpy version to 1.5
RF: up numpy and scipy dependencies as discussed
RF: drop scipy requirement to match travis-ci
Merge pull request #374 from matthew-brett/numpy-compat-fixes

MRG: bumpy numpy requirement to 1.5 / compat fixes
WIP: Started implementing cross-validation from model predictions.
ENH: A bit more work on cross-validation.
BF: The order of the output needs to be like the order of the data...

Also: some more flexibility on the model API that is accepted.
PEP8

Before I start mucking about here.
PEP8
PEP8
BF: Predict properly, by separating b0s and diffusion-weighted samples.
WIP: Work towards xval prediction in csdeconv.
DOC: optional arguments and their default values.
RF: Make this part of the reconst module, instead of its own thing.
RF + TST: Predict the signal from CSD model, check with kfold xval.
TST + DOC: Fixed test for csd xval, added reference for xvalidation on DWI.
RF: Removed some cruft.

This is related to prediction of DKI, which I leave for some other day.
PY3K
TST: as long as it runs...