This setting allows disabling/enabling showing avatars in hovers. We
already have settings for the explorer and blame gutter, so it makes
sense to also have one for the hovers.

Closes #419 - Make blame heatmap color configurable

Closes #209 - Open File in Remote should ask for a branch if no upstream

Fixes issue with new typescript
Pins node version to match vscode's version (7.9)

Adds menu & toolbar settings to the settings editor
Adds mode setting for settings editor
Adds sticky header to settings editor

Also adds icons for prev/next and places them into the editor toolbar