This commit adds functionality to the dragonfly plus model. The
functionality is to make whether source group rerouting and
intermediate router choice a configurable option that is set
in the config file.

To use said configurables, use these config variables in your
config file:

	source_group_rerouting= {"off" | "on"} default="on";
	intermediate_choice= {"leaf" | "spine" | "both"} default="leaf";

If source group rerouting is on, then if a packet is currently being
routed by a spine router in the source group, but the spine router
does not have a connection to the intermediate group, then the spine
will route the packet to another spine router within the source
group who does have said connection to the intermediate group.

If source group rerouting if off, then if a packet being currently routed
by a spine router in the source group cannot be directly routed to the
pre specified intermediate group in the message, then a new intermediate
router/group will be chosen from the list of possible intermediate
groups/routers that the source spine has connections to. It is not
rerouted within the source group.

Intermediate choice determines what type of routers can be chosen
as an intermediate router. If "leaf" is set, then intermediate routers
will only be of type leafs. Similar for "spine". If "both" is selected
then it could be either.

Additional features added in this commit:

New configurable:
	notification_on_hops_greater_than={"<int>"} default = MAX_INT

This new configurable sets the maximum number of hops allowed before a
printed notification of the number of hops that a current packet
is at is output to stdout. This is to help debug and know when routing
decisions are producing unexpected results.

Dfp online workloads broken

See merge request neil/codes!12

# Conflicts:
#   src/networks/model-net/dragonfly-plus.C

Revert "Merge branch 'dfp-online-workloads-broken' into 'dfp-online-workloads'"

See merge request neil/codes!11

This reverts merge request !10

Dfp online workloads broken

See merge request neil/codes!10