Besides being more clear about what belongs to which, this helps with
docker caching. The server and ui parts are only rebuilt when their
respective subdirectories change.
Extend this a bit further by making the webpack build not depend on
the target architecture. And adding cache dirs so parts of the server
and ui build process can be reused when layer-wide caching fails.
* Dockerfile which allows full build on ubuntu
* No cross-compile yet
* Fixed build scripts bug found with docker
Signed-off-by: Dolf Starreveld <dolf@starreveld.com>
