De-callback in favor of promises in the file APIs. Fixes #139
Added contributing guide and license information.
Added a "set newline mode" command binding.

Fixes #198.
Add an emergency reset menu item

Fixes #191
Fix bugs where project manager still uses callback style.
Added a workaround for Chrome promise bugs.
Revert Promises in file API to callbacks.

Promises do not seem reliable as they are in Chrome 34. Rather than
continue to implement hacks that can work around these problems, let's
just go back to callbacks. Maybe we don't need to be on the cutting edge
_all_ the time.
Bad variable reference in file manager.
Temp fix for #216
Better drag/drop feedback for tabs.
Fix bug that resulted from mucking with line ranges.

Partial fix for #205. Still needs a solution in order to restore folds
after we've trimmed all the lines.
Use Ace search to trim lines. Fixes #205 (for real this time).
Debounce tab rendering for a little less painting churn.
Fire session:render instead of manually calling renderTabs() to prevent bug when saving preferences.
Stop reloading preferences files on save, it's causing nothing but trouble.
Added splashy dialog transitions.
Focus default dialog if you click away from it.
Correctly de-register Ace's previous handler and register handler with Caret mappings unbound
Added transitions to the palette.
Fix for vim keybindings being lost on save, as well as other general remap bugginess