Provided by Roman Stolyarov
Integration, Refactoring, and Upstreaming by Solomon Peachy
X3II confirmed working by forum tester, X20 is nearly identical.
This includes bootloader, main firmware, and the flash image patcher.
Eventual Todo:
* Further refactor AGPTek Rocker & xduoo hiby bootloaders
* Further refactor AGPTek Rocker & xduoo hosted platform code
Change-Id: I34a674051d368efcc75d1d18c725971fe46c3eee
