Adding support for orphan blocks

Fixes #65, tested by using immature blocks as orphan.

* Adjusted blockupdate cronjob
 * Fetch block information via `gettransaction`
* Adjusted block class
 * Only getAllUnconfirmed where confirmations > -1
* Adjusted transaction class
 * added setOrphan method to mark orphaned transactions
* If block is orphaned
 * Mark all related transactions as Orphan_*type*
 * Set confirmations of block to -1 so it is ignored and marked as orphan
* Change transaction template, added listing for orphan transactions
* Add orphan status to block listings template