resolves #234 by adding an availablethrust variable to the craft
defaultthrottle should let users control the throttle when the sript ends
removed defaultthrottle lock because it was a bad idea
forgot to remove part of the lock
changes based on review comments
split up the helper class into its constitute parts
defined new extensions
started work on #236
a bunch of work on archive
added clarity to file loading exception
Merge branch 'available_thrust' into develop
Merge branch 'default_throttle' into develop
revert changes based on review comments