use custom and revert to fill-column or 80
fixed :lighter
highlight columns not chars, use overlays

highlighting will now begin at 80 columns in an Emacs buffer not 80
characters; tabs will no longer count as 1 column.

Instead of building regexps for font-lock, overlays are now used
to highlight text which is done using a jit lock function.
header update, and some spacing
checkdoc fixes
ignore .elc files
removed call to assert to remove cl dependency