This should eventually be rewritten to properly test IO features,
but this would be part of a bigger work on adding a proper testing
framework for Godot features.
Fixes#2454.
Works both for the editor and games.
Projects can still use "debug/settings/stdout/print_fps" to enable it
permanently. The --print-fps option takes precedence (so works even if
the project setting is disabled). That setting is also no longer redefined
on the fly based on the verbose flag, that was a mess.
Rémi Verschelde
Leon Krause
Michael Alexsander Silva Dias