Fix scoping issue on signup

closes #2429
Force preview to scroll to the end

fixes #958, fixes #535

- If the cursor is within the last 5 lines, then scroll to the end of the preview window, rather than using a ratio
Merge pull request #2428 from Decad/master

Fix scoping issue on signup
Merge pull request #2437 from ErisDS/cm-scroll

Force preview to scroll to the end
Add shim for codemirror on touchscreens

fixes #2385

- stolen the CM shim from js-bin
- if we're on a touchscreen device, don't use CM
- if we're on a touchscreen device, show a coming soon message for uploads
Merge pull request #2438 from ErisDS/cm-mobile

Add shim for codemirror on touchscreens
Fixes modal fading inconsistency problem by disabling jQuery's
transition and allowing CSS to do its thing

closes #2400
- Removed fadeIn, jQuery's animation
- Added show(), which only manages display, giving transitions to CSS
Merge pull request #2405 from nicksahler/master

Fixed modal inconsistent fade problem