fixes for LinkDelay test in test_hifi
adding linuxrouter.py
adding vlanhost.py
Merge pull request #363 from cdburkard/patches/testLinkDelay

Fix UserSwitch.connected() as well as testLinkDelay() in test_hifi
We need more than one iteration since the first iteration may show reactive forwarding and ARP delay; currently we have three for good measure, although two is probably enough.
adding documentation and test for linuxrouter.py
linuxrouter.py: changing name, printing routing table, and some more documentation
chmod +x vlanhost.py
adding test for vlanhost.py and adding vlantopo example
Merge pull request #361 from mininet/devel/linuxrouter

Adding LinuxRouter to Examples
Merge pull request #362 from mininet/devel/vlanhost

Adding VLANHost to Examples
adding comment to VLANStarTopo in vlanhost.py