Document dot_a_linkage
Updated Unofficial list of 3rd party boards support urls (markdown)
Add all MightyCore variants
Add MiniCore
Update specification version number
Added `includes` metadata specification
Add RedBear boards package json file URL
Updated Building Arduino (markdown)
fixed URL for OpenTracker boards
Add links for Windows 10 IoT Core support
Added Arduboy game system
Consistently specify compatible IDE versions as 1.5.x+ to include 1.6.x, etc.
Fix awkward wording of deleted library version removal schedule
Add MegaCore
Add clkdiv8 boards
Changes GitHub name for ATmega32M1 / ATmega64M CPU support.
Point Google Code page platform links to the Arduino IDE 1.5 3rd party Hardware specification