ONOS-6457 Improved bmv2.py mininet script

- Starts BMv2 with empty.p4 as when running with --no-p4 the switch
  crashes
- Automatically send a netcfg JSON to ONOS for each device
- Makefile to build all P4 programs (needed for empty.p4)

Change-Id: Ib872641751c543aac6c752610b1ce88a1a00d0d2
diff --git a/tools/dev/bash_profile b/tools/dev/bash_profile
index 9e7a549..65c7003 100644
--- a/tools/dev/bash_profile
+++ b/tools/dev/bash_profile
@@ -38,6 +38,10 @@
 # Setup default location of test scenarios
 export ONOS_SCENARIOS=$ONOS_ROOT/tools/test/scenarios
 
+# Setup path to Mininet custom scripts
+export ONOS_MN_PY=$ONOS_ROOT/tools/dev/mininet/onos.py
+export BMV2_MN_PY=$ONOS_ROOT/tools/dev/mininet/bmv2.py
+
 # Convenience utility to warp to various ONOS source projects
 # e.g. 'o api', 'o dev', 'o'
 function o {