Move typedefs/enums into a separate header
Add new utility classes for flux measurements.
Add utility classes for centroid algorithms
Add utility classes for shape algorithms
Header for flag utilities
Add utility class for algorithm flags.
Add namespace qualifications to typedef to unconfuse Swig

Swig seemed to think the "Flux" symbol was the one in afw (which will be removed
after the meas_base transition is complete), even though the enclosing scope is
meas::base.
Move constants.h content out of Results.h
Swig wrappers for new utility classes.
Modifications to FlagHandler
Finish new Algorithm interface
Swig for new Algorithm classes
Rework PsfFlux into new Algorithm interface.