Use files instead of sysctl to set limits

fixes #184

Replaced nodelist and nodemap in CLI with mn

Fixed locals bug (now they are persisent across calls)

Updated Mininet to be more compliant with dict
Fixes #182

Merge branch 'adf-userswitch-tclink' of github.com:adferguson/mininet into adferguson-adf-userswitch-tclink
Only sleep and reapply if slicing is enabled

Conflicts:
	mininet/node.py

Conflicts:
	examples/README

Conflicts:
	util/install.sh

fixes #159

pingall now reports fraction received

fixes #168

fixes #166

fixes #180

fixes #172

fixes #173

D'oh!  Next time test presence _and_ absense of an added env var.

OTOH, when people notice this quickly, it means they're using install.sh :-)

fixes #176

Dynamic Network with Remote Controller example; Extended LinearTopo

Simplified and refactored examples/dynamicnet.py

Developer dependencies are ~1GB

Cleanup and cosmetic changes.

Fix issue with mountCgroups not recognizing mounted cgroup

Extended LinearTopo to support mulitple hosts per switch

Extensibility Improvements

The script builds a network topology based on command line
arguments and uses a remote controller

This change uses the `Node.cmd` method instead of `Popen`. The `cmd` method
sends the input to a shell which may be in another namespace (if --innamespace
is in use), while `Popen` would always run in the root namespace.