Added -r|-reverse switch.

Searches for item to put down from last to first slot in range.
floor.bat now actually puts a floor down.
Reverted last change which was stupid.

It's running rect.  It's never close enough to the floor to see if there's
a hole.  Durrr.
Added wait-on command.
Added fuel check to prism.
Fixed wait-on free-slot.
WIP: debugging wait-on free-slot.
Modified floor.bat.

It now uses wait-on free-slot.
Added auto-fell.
WIP: Added some leaf-cutting for saplings.
WIP: More leaf cutting, clean up.
WIP: Typo.
WIP: Another typo.
WIP: Correcting erroneous ascent.

For some reason, turtle did not plant sapling, then began trying to fell a
tree.  Added extra check to ensure the turtle doesn't consider air a log.
WIP: Added 1 minute sleep.

This is to let more saplings decay.  Might make it configurable via
command line later to allow for trees with very low sapling drop rates.
WIP: Made place calls more resilient.
Fixed prism parsing of ltr and rtl flags.
Added wall program.
Added --list switch to update.
WIP: Modified how update stores remote packages.

It used to annotate the package table with some extra fields.  The problem
with this is that it means you can't easily iterate over available
packages.  So, instead of being {..., repository=..., branch=...}, it's
now {packages={...}, repository=..., branch=...}.