Allow ARP on veth devices (fixes #62)
recordshell: Don't print "connection intended for" messages
replayserver: Lowercase "text/html" content-type
debian/control: only require apache2-bin (not apache2)

apache2 actually runs the Apache server as a daemon, which
we don't need to require.

Fixes #60.
Fix race condition by blocking SIGCHLD
Let kernel destroy the veth pair (fixes #61)
Block signals early to prevent race condition
Add beginnings of abstract event loop support
Add WCONTINUED to catch suspend/fg with waitpid
Convert delayshell to abstract event loop
Eliminate ferry.hh/ferry.cc and clean up includes
Convert recordshell to new abstract EventLoop
Convert replayshell to abstract EventLoop
Move handle_signal to EventLoop code
child_process.cc: add safety check to make sure SIGCHLD blocked
Simplify run(), deal with SIGCHLD compression, ignore unknown SIGCHLD

Fixes #67
TempFile: Move apache-specific text to web_server.cc
Simplify TempFile
packetshell: run caching dnsmasq inside container

Closes #66
Give dns_outside the same port number in UDP and TCP

(because dnsmasq doesn't allow different)