use delay in virtual network

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>
provide a shared net delay constant

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>
refactor mock router

@whyrusleeping @jbenet

Are the Put and Get ops on the mock routing client intended to simulate
putting and getting from the network? If so, should the client put the
value locally and also add it to the network?

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>