Handle Bitcoin URI -- fill the Send Bitcoins form.
Keep active tab when switching accounts, even across devices

Needed for comfortable switching of devices/accounts after URI handler activation.
Account: Show block explorer link on tx mouseover. Receive QR links to addr info. GUI tuned.

GUI changes:
- Add account links in aligned to the left.
- Footer is aligned to the left.
- Content of Tx history, Send, and Receive is wrapped in a box.
- Receive address BIP32 is rendered in monospace font.
- Receive: "Show used" link aligned to match the position of "QR Code".
Add trezord support with plugin fallback, BIP32 CKD
Fix id/serialNumber dichotomy in trezorService
Estimate tx size without connected device
Send form enabled with disconnected device
Handle Bitcoin URI -- fill the Send Bitcoins form.
Add trezord support with plugin fallback, BIP32 CKD