Transactions in the queue are now capped to a maximum of 200
transactions. This number is completely arbitrary.

eth, core: interrupt the chain processing on stop

Removed chain manager's select/channel approach when checking for
interrupts. Now using an atomic int32 instead which checked for every
block processed.

core/vm: fixed strange output for trace logging & error reporting

Added an additional channel which is used to interupt the chain manager
when it's processing blocks.

Invalid named pipe name

ipc socket always uses default path

RPC refactoring