Automatic merge from submit-queue

e2e: Delete old code

These tests were added commented out over a year ago. Now they don't compile. The port forward test has a whole file devoted to replacing it (`e2e/portforward.go`) and while the exec test doesn't have a perfect replacement, it has several tests that cover for it (exec over a websocket, an e2e_node test, all the kubectl execs). If we want that test, it would be better to write it fresh anyways.

cc @ncdc