Revert "Need to test, but added ICMP"

This reverts commit b275e91a945ed58f653f6adf9fca13ed6a078064.
Fixed bugs regarding cache

Cache should work now, please look at the cache output on ./sr window
to confirm that handle request is sending and receiving the correct arp
requests
Fixed bug in ip routing and now wget worksc
Aded back in sr_icmp files