working functional profile example
ModelFunction -> PDF in bumps
better handling of examples
fixup docs
better handling of examples
move startup logic from script to package
update tests
update paper link
allow scattering factors to be cached when fitting material density
git complains about CRLF
Merge branch 'bumps-split' of github.com:reflectometry/refl1d into bumps-split
Merge doc fixup from branch