bench: Add read-stream throughput
bench: Add fs write stream throughput
bench: Remove io.js

Better covered by the other benchmark/fs scripts.
bench: Make io.c output easier to read
bench: Move tls-connect into benchmark/tls

Also, make it work properly with current node.
bench: Replace tls-fragmentation with tls/throughput
bench: Remove old run script
make: Add benchmark make targets
bench: Fail gracefully if function_call binding fails
bench: Add --html to compare script
bench: Show % change rather than % difference
tools: Add wrk for benchmarking http servers

https://github.com/wg/wrk/commit/6d143f164d43aece6b488cc0e6c8dfece572ece1
bench: Use wrk for http benchmarking

Fall back to ab if wrk fails to compile, or on sunos.