load add-ons (autoload libraries) on reset session
coerce NULL to list()

there must be a terser way to do this
fix copy and paste error
basic rcloud.viewer

it shows stuff. it might be in the wrong order though.
style viewer row & column headers better
order viewer columns correctly
Merge branch 'develop' into add-ons
attempt at settings pane and optional command prompt
fix logging of errors when there is no session pane

print the text(): not perfect, but better than not logging at all
Merge branch 'develop' of https://github.com/att/rcloud into develop
signal errors in notebook.R via HTTP error code; pass-through call errors
Merge branch 'develop' into add-ons

Conflicts:
	htdocs/js/rcloud_bundle.min.js
add an order of magnitude to panel sort order

leave lotsa room for customization
toggling command prompt

My First Checkbox
toward #876

this almost works - but load order is wrong
fix command prompt option versus readonly interactions

closes #876
show side pane collapsers at load

for #875 (but welcome message still showing too early)