Some JSRE methods (PrettyPrint, ToVal) bypassed the event loop. All
calls to the JS VM are now wrapped. In order to make this somewhat more
foolproof, the otto VM is now a local variable inside the event loop.

p2p/discover: evacuate self from node database during iterations

core/vm, rpc: added disasm to `ext_` RPC

core: added RPC sign back in

Add StateTests/RandomTests and VMTests/RandomTests

make registrar available in console

automatic DAG pregeneration for smooth epoch transitions

Fix two additional download vulnerabilities

- backend: AutoDAG bool flag passed from cli/eth.Config to ethereum, autoDAG loop started if true
- backend: autoDAG loop start/stop, remove previous DAG
- cli: AutoDAG bool flag, off by default, but automatically ON if mining
- admin jsre: add startAutoDAG stopAutoDAG and makeDAG in miner section
- switch on/off DAG autogeneration when miner started/stopped on console

prefix dapp key/value entries in extradb

Tests updates

Cleanup

core/vm: optimisation on RETURN and updated tests

Storing tx receipts in extraDb

CLI, JSRE admin and  Solc improvements 

eth/downloader: fix test to it doesn't time out on a slow machine

eth: fix odd method names in peer set