Closes#2984, #3020
Ref #1463, #3019
#### Shortcut Values
Shortcut values can now be either strings (as before) or objects like
{action:string, options:hash}.
#### Markdown shortcuts added
- 'ctrl+alt+u' strkethrough
- 'ctrl+alt+1' h1
- 'ctrl+alt+2' h2
- 'ctrl+alt+3' h3
- 'ctrl+alt+4' h4
- 'ctrl+alt+5' h5
- 'ctrl+alt+6' h6
- 'ctrl+shift+i' image
- 'ctrl/command+k' link
- 'ctrl+l' list
Left behind commented out stubs for additional markdown shortcuts.
#### Editor Controllers (New and Edit)
- Moved shared init function into editor-base-controller.
- Removed MarkerManager mixin from editor controllers as it's included in
the base.
Closes#2988, #2752
Ref #1463, #2984,
# Shortcuts via Keymaster
- Added KeyMaster to bower dependencies. KeyMaster is a minimal keyboard
shortcuts library.
- Added `ShortcutsRouteMixin` for routes that will use shortcuts.
Currently, only routes can have shortcuts. See the extensive comment
at the top of `core/client/mixins/shortcuts-route.js` for a
description of how to implement shortcuts.
## Other Changes
- Injected popover service into ApplicationRoute
- Created `EditorRouteBase` mixin for the `editor.new` and
`editor.edit` routes to mixin.
- `StyleBodyMixin` now calls `this._super()` on `activate` and
`deactivate` to play nicely with other mixins.
## Shortcuts and Stubs implemented
#### Application-Wide
- `'esc':'closePopups'` shortcut **stub** to close popovers,
modals, and notifcations
#### Editor Shortcuts
- `'ctrl+s, command+s': 'save'` note that `command` is the
`meta` key.
- `'ctrl+alt+p': 'publish'`
- `'ctrl+alt+z': 'toggleZenMode'`
