Improve debugging printouts

Include both the request endpoint and the parameters, as well as the
json response.
Implement actTakePicture API call
Add a FIXME about actTakePicture calls returning early
Simplify the _apicall function

Allow for key/value function arguments instead of having to pass a brand
new dictionary as an argument.
Implement awaitTakePicture API call.
%r already quotes string arguments.