misleading errors if not authenticated

[rdp]

authentication doesn't seem to be handled...

For feedback sake, if one forgets to authenticate, seemingly unrelated
errors are thrown...expected?

 $com.familytree_v2.pedigree :me
TypeError: can't convert nil into String
        from C:/installs/Ruby187/lib/ruby/gems/1.8/gems/ruby-fs-
stack-0.5.3/lib/ruby-fs-stack/fs_communicator.rb:181:in `+'
        from C:/installs/Ruby187/lib/ruby/gems/1.8/gems/ruby-fs-
stack-0.5.3/lib/ruby-fs-stack/fs_communicator.rb:181:in `add_session'
        from C:/installs/Ruby187/lib/ruby/gems/1.8/gems/ruby-fs-
stack-0.5.3/lib/ruby-fs-stack/fs_communicator.rb:172:in
`set_extra_params'
        from C:/installs/Ruby187/lib/ruby/gems/1.8/gems/ruby-fs-
stack-0.5.3/lib/ruby-fs-stack/fs_communicator.rb:73:in `get'
        from C:/installs/Ruby187/lib/ruby/gems/1.8/gems/ruby-fs-
stack-0.5.3/lib/ruby-fs-stack/familytree/communicator.rb:275:in
`pedigree'
        from (irb):17
        from :0