Hop: moved a bunch of functionality out of the core library definition file
Hop: added part refs
Hop: more todos

especially tests, dude
moved hop exec to bin dir
updated pubspec
the big clean out
pubspec, readme, change log updates
removed io -> getting this from bot
compile_docs: notes on broken daartdoc due to issue DARTBUG 5218
stop echoing the command being executed for hop
runner: remove args parsing output -> doesn't do anything

adding print raw task 'hidden' command
_hop_state: introduced notion of reserved task names
fixed the signature of addTask
_hop_runner: smarter about handling null (or other values outside check mode) returned from a task
added a simple about task
Added completion script
lots of readme fun
library name: bot_hop -> hop
hop_runner: using new import syntax
make _HopRunner.run explicit