rework of ui and refactor of code. script window now displays below
instead of in a new pane. cmd-i toggles script window to run or
end and hide. ctrl-c kills script without hiding window.
changed title.html to title.txt. added methods for error display and for
output display
consolidated output to display function for both errors and standard
output
start/show, close/end, and stop script functions working. updated
keymaps and menu options.
Switch event name to just run, use ⌘-i
Merge pull request #30 from rgbkrk/ui

[WIP] Show output in lower pane