There was an official website of Toshiba called "FlashAir Developers '', and
there was information necessary for FlashAir development, but since it closed in September 2019.
Instead, I will point an archive site for developers.
W-04 needs to use CMD17 instead of CMD48 to retrieve iSDIO register memories.
To supporting both W-03 and W-04 card, I changed the readExt() code to use CMD48 first and use CMD17 if it returned some error.
This method is from the FlashAir developer sample code.
https://flashair-developers.github.io/website/docs/tutorials/arduino/2
Timing functions (millis, micros and delay) replaced in whole source, defined in Marlin.h.
This commit enables original implementation (SYSTEM_TIMER_2 undefined)
Verified with passed complete wizard process.
