Merge pull request #10 from sgallagher/master

Add .gitignore file
correctly invoke execute() for non-session commands

End point commands can now specify, how many positional arguments are
required for associated function.

Fixes error when trying to invoke exit command in interactive mode.

Added command-creation time check for positional arguments count.
added dependency on openlmi-tools to setup
fixed handling of long options

Long options passed to commands caused usage being printed.
Add explicit requirement on docopt 0.6

We rely on the availability of the options_first argument