* 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.
* Initial version of gdbstub support
* Add DEBUG argument to Makefile to add more debug data and turn off -Os
* Add the output redirection handling
* Added documentation
* Cleaned up the english a bit
* Make gdboutput actually trap all the output
* Review comments