add Apache::Request#flush method for Kernel#spawn.
suppress rb_warn message.
Merge pull request #4 from nishidayuya/suppress_rb_warn

suppress rb_warn message.
output Ruby version at ruby_startup on Ruby 2.x.
output ruby_patchlevel at ruby_startup.
Merge branch 'add_flush_to_request_class'
Merge branch 'output_ruby_version_on_ruby_2_x'