v1.0.0 Boards Manager install support

[per1234]

Boards Manager URL for testing: https://raw.githubusercontent.com/per1234/MegaCore/bmtest/package_MCUdude_MegaCore_index.json

Boards Manager entry:

Boards Manager URL after this PR merged: https://mcudude.github.io/MegaCore/package_MCUdude_MegaCore_index.json

[MCUdude]

Thank you so much! After some more testing it would be nice to add to to the "Arduino on other Atmel chips" page.

[per1234]

You're welcome. Also should be added to https://github.com/arduino/Arduino/wiki/Unofficial-list-of-3rd-party-boards-support-urls I'm happy to do that if you want, just let me know when you think it's ready.

[MCUdude]

I haven't received my ATmega128 test board in the mail yet, so I still haven't been able to squeeze out any bugs by testing yet. I'm sure the code will run, but Murphy's law always gets me ;) In the meantime I'm thinking about improving the documentation of this core. Topics like "How to port a library" may come in handy for some. Any topics you think should be added?

[per1234]

One thing to consider adding to the documentation is a note that if any of the libraries included with MegaCore are updated using Library Manager then the version installed with Library Manager will override the MegaCore version of the library. See arduino/Arduino#4064 for more information. I haven't been able to find any workaround for this issue other than to document the issue and tell the user they should move the updated library from their {sketchbook}/libraries folder to {IDE install folder}/libraries(for example: JChristensen/mighty-1284p@ceed9b6). It's a difficult concept to explain without adding a lot of text to the documentation. There is currently some work being done towards a fix(arduino/arduino-builder#123) but so far it only completely addresses the issue with cores that use other architectures so doesn't help every library included with MegaCore and MightyCore(arduino/arduino-builder#123 (comment)). Even if the issue is fixed there will still be lots of users on the previous versions of the IDE that still have the issue.

[MCUdude]

I got the ATmega128 breakout board in the mail today, and it works like a charm! 😄 I think it's ready to be published on the "Arduino on other Atmel chips" and "Unofficial list of 3rd party boards" page. Now I need people to test it and let me know if there are any bugs

[per1234]

I've added MegaCore to both pages.