Opentxs CLI commands separation

Yes, I know this is a big PR. ot_commands_ot.cpp was a big file to split.
http://www.cplusplus.com/reference/map/map/empty/
> Returns whether the map container is empty (i.e. whether its size is 0). This function does not modify the container in any way. To clear the content of a map container, see map::clear.