Import tota-ua
This commit imports tota-ua from commit
a0c2c06cf ("Add return 0
to log functions to prevent unexpected failure").
Following changes were made with repect to original tota-ua repository:
- naming is adjusted (tota-ua -> upgrade/upgrade-engine)
- delta.ua is dropped along with libtota depencency
(currently it brings only unsupported and faulty delta_fs
upgrade type)
- actual programs are moved to src/ subdir, scripts moved to scripts/
- CMakeFiles.txt are considerably simplified, dropping most of the
duplication
Change-Id: If7da44c748e3e25b4519022fb292088ed8cbdcc0