Various improvements to P4 dev env

- Better handling of BMv2 crashes in bmv2.py (with watchdog and logging)
- bm-* commands for easy access to BMv2 log, CLI, etc

Change-Id: I1c79acda641171566d8e1162442c7f377bb273fe
diff --git a/tools/dev/p4vm/user-bootstrap.sh b/tools/dev/p4vm/user-bootstrap.sh
index 9b19f26..b7a7739 100755
--- a/tools/dev/p4vm/user-bootstrap.sh
+++ b/tools/dev/p4vm/user-bootstrap.sh
@@ -12,6 +12,7 @@
 # ONOS
 export ONOS_ROOT=~/onos
 source ~/onos/tools/dev/bash_profile
+source ~/onos/tools/dev/p4vm/bm-commands.sh
 EOF
 source ~/.profile