try initial calls of bellmanFord()
add rules correctly
remove device, remove switch, move device functions
Update L3Routing.java

added host to list in deviceAdded, added switch to switch list in swtichAdded, added BF call in switchRemoved
Update L3Routing.java

added pseudo-code to remove old rules in linkDiscoveryUpdate() - todo later
added rule removal commands
removed calls to removeRules()
remove rules and fix dumb mistake
L3Router - Fixed Removal of rules
Remedying copy-paste syndrome with bellmanFord() and bellmanFord( host )