GetConfig returns an upgrade config with the provided fork scheduled to have been initially activated and all other forks to be unscheduled.

GetConfigWithUpgradeTime returns an upgrade config with the provided fork scheduled to be activated at the provided upgradeTime and all other forks to be unscheduled.

SetTimesTo sets the upgrade time of the provided fork, and all prior forks, to the provided upgradeTime.

Fork is an enum of all the major network upgrades.