Have the file and debug options be set once when starting the CLI

[csisl]

When the CLI starts, it would be ideal to provide the debug level and path to the file just a single time. After that, any command can be run with those settings. This might not be supported with click, but it should be doable with cliff.

[csisl]

Found out that you can use pass_context to halfway solve this issue, so the debug level and file path can be set once when the program starts up. This can be seen in commit 212f60c. However, I haven't seen how to keep the program running and keep entering commands. I tried with a simple while loop in main, but that didn't work. This issue will remain opened until that is complete.