This corrects two critical bugs, both of which are thought to date to 1.5.9 but were not reported until post-1.5.10 - disabled millis was busted... and... so was PWM, on 6 or 12 pins (depending on pincount) DA/DB series, leaving only 5, 6 or 7 pins capable of PWM, and most of those were the worst pins for PWM. At some point after I ran the pwm tester last, and 1.5.10, the pwm broke, while I think the millis one must have been much more recent, as I use disabled millis all the time, plus making several other assorted improvements.
Also fixes excessively bloated windows toolchain package and bad versions of eeprom.h and power.h builtin libraries.