some reorganization to allow more flexible running of behavioral scripts

this code is currently running on vogel. there are some small changes and some big changes. the big ones:

this adds a new script to the path called `behave` which allows us to run any behavioral protocol without building out the full `if __name__=="__main__"` every single time

instead, we run `behave -P 1 -S B999 TwoAltChoiceExp` to run subject B999 on a two alt choice experiment on panel 1.

this should simplify the process of starting up a new behavioral protocol. currently if you have written a protocol, you need to do a few things for our Perl scripts that manage the panels...
1. make sure Python file containined the protocol is executable
2. add the protocol file to the path
3. add the protocol file to the `xstart` perl script

now we have a few improvements:
1. we can maintain more than one protocol per file
2. we only need to register a python module containing behavioral protocols with the pyoperant local config rather than needing to register every single protocol
3. loading of config files etc is all in `behave` now, so any bugs in loading protocols can be dealt with there.

finally, to deal with the new command format, I've replaced `xstart` with `pyoperantctl`

minor changes:
- during shaping, you'll now receive a "warning" email when transferring between blocks