This brings over some features that were added to the netdev interface,
most notably the separation between the name and the type. In addition
to being cleaner, this also avoids problems where it is expected that
the local port has the same name as the datapath.
No conflicts, but lib/dpif.c needed a few changes since struct dpif's
member "class" was renamed to "dpif_class" in master since sflow was
branched off.
At startup, the vswitch needs to delete datapaths that are not configured
by the administrator. Until now this was done by knowing the possible
names of Linux datapaths. This commit cleans up by allowing each
datapath class to enumerate its existing datapaths and their names.
The dpif and netdev code has had various ways to check for changes to
dpifs and netdevs over the course of Open vSwitch development. All of
these have been thus far fairly specific to the Linux implementation. This
commit is the start of a more general API for watching for such changes.
The dpif-related parts seem fairly mature and so they are documented,
the netdev parts will probably need to change somewhat and so they are
not documented yet.
This commit initially introduces only a single datapath implementation,
which is the same as the original one, but it paves the way for
additional implementations, such as the upcoming userspace datapath.
