Previously only top-level data elements could be overridden in a map or
extended profile entry. This change adjusts map and profile evaluation
to use a recursive merge using salt.utils.dictupdate.update().
This is a break with compatibility, but in the common case a cloud
profile or map is not structured to truncate configuration but to add
further detail to the profile that it extends.
Update map docs with an example from VMware where we chan now change a
network parameter without having to repeat other device information such
as disk controllers.
