Remove unused utility functions, remove old vars object on Shells.
All request that don't return data return a 204.
The command being composed is saved when navigating history.
Merge pull request #219 from FuegoFro/empty_server_results_return_204

All request that don't return data return a 204.
Merge pull request #218 from FuegoFro/remove_unused_util_shell.vars

Remove unused utility functions, remove old vars object on Shells.
Merge pull request #222 from FuegoFro/history_remmeber_next_command

The command being composed is saved when navigating history.