Construct input tasks in multiple steps to allow input task reuse.  Fixes #407.
partialInput/fullInput methods on InputTask to apply input programmatically. ref #407.
expand input task documentation. ref #407
use .evaluated instead of .value for InputTasks
launcher: put ivy resolution cache in boot and clear each run, ignore original resolver
Test case showing that cached resolver is not ignored
ivy cache: ignore the original resolver in more places. Fixes #704