TAP memory leaks:

TAP memory leaks:

1 - use bit-map to re-use ID values and thus VLIB nodes
2 - free vrings
3 - free hw_address on HW interface delete (a HW * struct is memset on pool_get)
4 - free temporary node names during TX node setup

Change-Id: Id114c8bb9c844fd4ceb02fbbeb4b511ecfeb61ce
Signed-off-by: Neale Ranns <[email protected]>