fixes #8789 - adds correct link for information about cpu shares
fixes #7867: container creation wizard now tracks state in dedicated objects
Refs #7867 - Container wizard state refactor
fixes #8342 - disables form buttons on new container page in absence of docker compute resources
Fixes #8637 - local registry container support

Prior to this commit, one could not start containers connected to a
local or non docker hub external registry. This is because the container
parametrize call did not properly prefix the registry url in its Image name.
This commit fixes that.