renderer

Merge branch 'remove_dynamic_mem_from_spectrum_class'

New spectrum class in progress. Basic functionality works; but not yet itnegrated into rest of renderer.

Fixed up 3D Vector class to properly overload operators. Now binary operators taking a scalar and a Vector are written as non-member functions, and thus we avoid the "ordering problem." Also added some documentation for the Vector class.

Documented the code in RegularlySampledSpectrum.

Working on new regularly sampled spectrum code.