add polymorphic comment table
add comments view folder
create comments migration
add comment spec files
initialize (@improvement -> Improvement.new) so the improvements form that renders from problem show can hold an improvement object in the form_for
create methods to access commentables in improvement/problem/solution
add form partial for improvements
update routes to accomodate comments
log key parameters
add ajax method receivers for category specific comments
git glitch on spacing
add comment schema