docs: Adding README, COPYING, and AUTHORS

Change-Id: I37b3f5fa98530645ca4dee5ed4abac2d1bd49cbf
build: Fix compilation errors and deprecation warnings

Change-Id: Ibbe2d30ced038f0c46a8669b5957b68c4f265350
src: Update license to GPL 3.0

Change-Id: I79d18746f51f630dc78b0b97b8081bb9c8dce5d5