intensity fxn helpers
comment fix
project volume accepts input for interpolation method
update comment
update GUI for obtaining interp method
add test for interopt
Merge branch 'interpOpt' into threshOpts
values below threshold set to surface color
range shown on projection
update prompt opts
bug fix
unborked redrawSurface

reinserted scalar color maps. Fixes loading of images with colorMaps
(e.g. stroke.mat)
colorMap name not integer

projectVolume now has user specify color name, vertex colors saved as
scalar magnitude rather than RGB (helps precision, allows user to
change color scheme later).
use scalar vertex colors til redraw surface
test fix
close projections added again
more intuitive title
better node support

node sizes adjusted for object size, allows comments in node files,
expanded tests, fixed addLayer bug where smooth of zero (none) caused
an error.
closing tracks or nodes now opens demo object

Demo object created whenever no track, layer or nodes are present.
remove name value from test for proj volume