layerman: add meta-atmel, meta-exynos and meta-dominion

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
ci-upload-helper: ensure image directory exists

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
CI helpers: use 2014.12 as version

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>