t/perl/test_sleepy.psgi: perl test file that sleeps a bit

This is to test non-CPU bound servers that are waiting on
something (e.g. a database), expecting that we can have a lot more than
num CPU cores of these and not see performance degration.
t/perl/hello_benchmark.pl: silly benchmark for CPU count + thunder lock

This is to test how the number of processes and using thunder-lock or
not affects response times.
Merge pull request #613 from avar/more-perl-tests-and-benchmarks

More perl tests and benchmarks