implement history forever

[daretodave]

history of commands executed should be saved to ~/mterm/history

a flag should be in settings to save history output, default to false a flag should be in settings to save history at all, default to true

ctrl+r should pull up historical execution

the runner should default with nothing in history BUT should load next item on Arrow Up

• if history execution is not saved, load just the prompt - this should always be saved
  • only then is it added to the stack on the UI
    • this avoids UI overload from e.g 5000 history items

this is queue up for #27 search will scan ~/mterm/history for prompts and optionally results if flag is enabled