v1.3.1 catch up with changes from PrintPY2040

Catches up with a change I made for the (now released) PrintPY2040 project @ https://github.com/easytarget/PrintPy2040

• Timings are now handled internally as ticks_us rather than ticks_ms
• Also remove the PrintPY prototype tree
• A few documentation fixes

v1.3.0 : Add option to skip firmware test

A new option has been added; noCheck = True at init() will skip the M115 firmware check.
Useful for pre v3.6 RRF versions where M115 does not respond while simulating.

v1.2.0 : remove compatlib.py

The requirement for compatlib.py to be included along with the main class is removed.

• It's functionality is now handled in serialOM.py itself
• I was meaning to do this before the main release but is slipped through the net

Note: the latest printPy2040 code is also included, with pretty fonts but no useful output yet.

Reliability fixes

Fixes to the data gathering loop and sequence handling:

• A 'greedier' response gathering routine that will correctly empty the recieve buffer and process all data there even if responses are arriving out of sequence. This protects against console feedback messages causing sync issues
• Sequence number updates and recording handled at a lower level, removing the potential for a failed 'verbose' request to be ignored
• Garbage collect after every model update, as well as after every request, a relatively aggressive strategy
• Plus a few debug and error handling/message fixes

fix potential out-of-sync if a verbose request fails

BugFix release:

Fixes #1 , a potential issue where a failed verbose request could be ignored, leaving the local OM out of sync with the host model.

Initial; CPython release

CPython working, seems stable in testing.

• microPython is a WIP