* Rebaseline firmware to non-OS SDK version 3.0
* Note that SDK version 3.0 introduces the concept of a Flash Partition Table(PT). This is located at Flash offset 0x10000 in our firmware build.
* The firmware is now PT aware with both LFS and SPIFFS taking their partition size and location from the PT
* A new tool `tools/nodemcu-partition.py` is now used to initialise these data and can also download LFS and SPIFFS images to these partitions.
* Add FatFs
* enable BUILD_FATFS for all-module build
* push vfs into rest of firmware
* align maximum filename length
* increase timeout for acmd41 during card initialization
* switch from DOS to Unix path semantics chdrive() is substituted by chdir()
* update to fatfs R.012a incl. patches 1-6
* add callback for rtc provisioning in file
* update docs