Universal keyboard shortcuts

Use the same keyboard shortcuts across websites to do things like moving the cursor to the Search field, creating a new message, or entering distraction-free mode.

Currently-supported actions:
- Search (keyboard shortcut: "Alt+S"): Move the cursor to the site's search field
- Create/Compose (keyboard shortcut: "Alt-C"): Create or compose a new entry/post/etc.

Actions wishlist:
- Create a new message/post/etc.
- Toggle distraction-free mode, which hides or minimizes sidebars, footers, nav bars, etc.
- Save/Submit the current post or form
- Edit the current page (if the site provides editing capabilities)

Currently supported sites:
- Amazon.com
- LinkedIn.com
- Ebay.com