Add backup, update API, start creating exchange

Added in a 15 minute backup for database and wallets (not shown in code)
Added new AllCrypt based API calls. (Unfinished. AllCrypt API call will
be added along with API docs)
Removed "New" label from pool on navbar.
Removed Claim Address page.
Changed getstats API method to base difficulty on the latest block in
the database instead of an RCP call.
Fixed error in API docs.
Added in exchange page. (Unfinished)
Changed the way pool url's are displayed
Fixed block forking bug on explorer.