Get rid of parfor

The defaults on Matlab's parallel toolbox result in a slower performance
rather than faster. If someone really needs speed, he can manually add
the parfor back in.
Dosing sensitivities

All the functions requiring sensitivities have been updated to
incorporate dosing as described in issue #7. This includes fitting. Left
out is LNA and MFK which never get love and curvature-requiring
functions, which are broken for other reason (#9).