for user injection and added test on write privilege by ownership.

Changed separator for group_write property to " " in 
CreateNodeController for consistency with NodeDAO

ContainerNode then throw ContainerNodeNotFound exception

didn't use new Mock Filter for User injection, will include it later

Added Maven profiles for loading io.zonky.test.postgres dependency dinamically according to detected OS

to pom file. Needed for testing on local windows machines. We can remove
it later just in case.