[ts paths] Fix bug with relative paths

If a non-existant relative path not prepended with ./ was given to
ts.create(), then it would fail as it couldn't determine the dirname to
create.
[ts paths] Better striping of trailing slashes

Trailing slashes fuck up basename and dirname, so we remove them if
they exist. This removes the literal '/', and uses os.pathsep, and also
makes removing trailing slashes the first thing that happens when
working with either ts.create or the ts.path property.
added plotting of segmented image
corrected order of image channel
added option to write image to timestream right after color correction stage
added a pipeline demo to only create and save fully corrected images
added a pipeline demo with processing time constraint from 8AM to 3PM