Automate startup of node, with regards to consensus

[jules]

With both the provisioner component and the generation component not being dependent on a specific hash, and with both now able to update their values when a tx expires, we can make the node even more easy to use by automating the syncing, staking, bidding and starting of consensus components without any need for user input.

Some handy added features would be specifying a --wallet flag to start the node without consensus running, and adding some commands that can adjust default locktimes and values for automated transactions.

This enhancement should remove the need for node operators to consistently check if their transactions have expired and from sending new ones in due time by themselves, which is much less of a drag. This replaces #13, since a user can no longer accidentally start consensus components on the wrong round this way.