package.bbclass: Import changes from dora

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
devshell: Fix indentation

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
cmake: Upgrade to 2.8.12.1

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>