Default flag-format

[eljeffeg]

This checks to see if any flag-format has been provided and instead of failing with an exception, sets a standard default format of S+{.*?}. Prints a message to the user that it's using a default flag format.

This allows you to just run $ katana after install without any configuration errors / issues, bringing you to the prompt where you could set the flag-format if you need to, rather than requiring it from the command arg or ini.