Cursor position is wrong when scrolling

[benbro]

Tested with the online demo, FF 31.0, Windows 7, quill v0.17.0

To reproduce

• Open the online demo http://quilljs.com/examples/
• Press Enter few times until you see a scroolbar
• Scroll to the bottom on both editors.
• Place the cursor and see that the cursor position is few lines above in the other editor.

Another issue is the fact that the scroll position is not synced between participants which might be desired.
#183

[benbro]

Thank you for the fix.

[jhchen]

Thanks for reporting!