Add ruby-prof option to benchmark
pull in minitest for benchmarking
port existing tests to minitest
two passing benchmark tests
remove assert_nothing_raised
Merge remote-tracking branch 'origin/master' into add-ruby-prof

Conflicts:
	test/generator_test.rb
remove the other assert_nothing_raised
make performance tests less picky
Merge branch 'master' into add-ruby-prof

Conflicts:
	test/message_test.rb
Merge pull request #45 from protobuf-ruby/add-ruby-prof

Add ruby-prof option to benchmark