Change minimum focal offset to a much smaller value.
Add spherical and cyllindrical projection options.

Projection mode is now a drop-down menu/enum rather than
parallel/not-parallel checkbox/boolean.

For now, spherical and cyllindrical projectiosn are always use
dof = infinity.

FoV slider now acts as a guide; much larger and smaller FoV values
can be used if typed manually.  Projector objects are responsible
for clamping those values to prevent errors.

Min and max FoV values (used for sliders and also some other places)
are pulled from projectors' recommended values rather than being
static values in the Camera class.
Rewrote DoF effect so that it now works with all projections except parallel.
Simplify and improve projections.

DoF can be used with all projection modes, including PARALLEL.
Fix misspelling of 'cylindrical' (had too many 'l's).
Remove unneeded TODO.
Back up ray origin *after* aperture simulation for parallel projection mode.
Replace special case to offset parallel camera with additional wrapping projector.
Change names of projectors to be more descriptive.
Fixed code style
Don't use java.lang.Math in QuickMath.clamp
Include version in zipped folder name