Allow to disable fast loader feature

[maccasoft]

SimpleIDE 1.1.0 uses the new fast loader feature which sets the serial port speed to 920k or so and may not be compatible with third-party USB-serial converters. Please add a configuration setting to disable the fast loader and set the port speed to a maximum of 115200 bps.

[jsdenson]

This is most likely a loader issue. Do we have any control over this from the loader command line?