Webbased repl
Doesn't run twice on Ctrl+Enter anymore

Event was fired on key up and key down. now only on down, I chose down
so I can stop the return from getting added to the code.
Give the editor a fixed size so it scrolls
read builtin modules
don't evaluate import statements.
check for multiline strings
t push origin masterMerge branch 'albertjan-web-repl'
Merge branch 'master' of github.com:bnmnetp/skulpt