* Add network proportion to homepage and /vspinfo.
Proportion is calculated using the number of tickets currently registered with the VSP, divided by the total size of the network ticket pool as reported by `getblockheader`.
The value will only ever be an estimate because:
- it's possible for a single ticket to be added to multiple VSPs.
- vspd does not distinguish between immature and live tickets, whereas `getblockheader` only reports live tickets.
- `getblockheader` is reporting the size of the ticket pool as of the previous block, not the current block.
* xaur suggestions
* Show missed ticket %, not just the raw number.
- Use bootstrap to improve layout.
- Add warning banners for webserver debug mode and vspd closed.
Admin page:
- Replace listing of all tickets with form to search by ticket hash
