Allow registering MNs without actually starting them
Allow registering MNs without actually starting them

This can be done by calling prepare_masternode() when inside run_test.
Also implement remove_masternode() which spends the collateral.

thelazier/dash,nmarley/dash,UdjinM6/dash,ionomy/ion,nmarley/dash,ionomy/ion,dashpay/dash,dashpay/dash,nmarley/dash,thelazier/dash,ionomy/ion,UdjinM6/dash,UdjinM6/dash,ionomy/ion,UdjinM6/dash,ionomy/ion,dashpay/dash,dashpay/dash,nmarley/dash,UdjinM6/dash,nmarley/dash,thelazier/dash,nmarley/dash,dashpay/dash,nmarley/dash,thelazier/dash,ionomy/ion,thelazier/dash