Suggested additions to Arduino_Core_STM32

[AndySymons]

Dear fpiSTM,
As discussed on STM32duino, I am presenting two suggested additions; I am grateful for your offer to raise the PR(s). My private message to you on STM32duino gives more details. I attach a ZIP file with the referenced code. You are welcome to edit it as you see fit. I confirm that I claim no copyright to this code (though would appreciate a credit) and am happy for you to issue it under the usual terms.
Kind regards,
$Andys boards.zip
Andy

[fpistm]

Hi @AndySymons
Thanks I will look at that and submit appropriate PR.
About credential, you will be the author of commit ;)

[fpistm]

#376 merged