[experimental] Add a renderLine event, and a demo that indents wrapped lines

These changes are experimental, not documented yet, and might not end up
in the stable API.
Take vertical padding into account when scrolling cursor into window view
Stop assuming that top padding equals bottom padding
Make continuelist.js addon work.

It had been depending on the list token being highlighted
with the class 'string', which it no longer is in the markdown
mode.

Updated to check the `list` property of the line's state.
[continuelist addon] Fix changes to not rely on line.stateAfter
[javascript mode] Handle getter/setter definitions better

Closes #1336
Add a margin parameter to scrollIntoView

Closes #1337
Make coordsChar less easily confused by margins
livescript mode
[livescript mode] Integrate
Set viewportMargin to Infinity in the autoresize demo
[addon continuelist.js] Make the listiness check

Just a small nit. Without the list check, `getStateAfter`
looks like it will always be true.