* Bring fastpin_avr in line with standard defpin macros (to simplify porting document notes
* checkpoint - bring all the arm and esp platforms in line w/defpin macro naming/ordering
* checkpoint - update PORTING.md to include information around just adding pin definitions if needed
* Kick all the pin definitions to allow for some runtime querying of ports and tweak pintest to have it provide pin definitions for platforms that have port definitions but might be missing pin specifics (e.g. not yet-supported avr platforms
