Add the install/update options to the option parser.
Sets up the resolution process @return [void]
Creates the initial state for the resolution, based upon the {#requested} dependencies @return [DependencyState] the initial state for the resolution
@return [Boolean] whether or not the given state has any possibilities
left.
@return [Array<Array<Object>>] The different requirement
trees that led to every requirement for the current spec.
Removes a possibility from ‘self` @return [PossibilityState] a state with a single possibility,
the possibility that was removed from `self`