Fix a whole bunch of Ruby 1.8.7 bugs

There are still 4 test failures:

* rspec ./spec/fpm/package/rpm_spec.rb:297 # FPM::Package::RPM#output package attributes should have the correct 'after_target_uninstall' trigger script
* rspec ./spec/fpm/package/rpm_spec.rb:288 # FPM::Package::RPM#output package attributes should have the correct 'before_uninstall' trigger script
* rspec ./spec/fpm/package/rpm_spec.rb:279 # FPM::Package::RPM#output package attributes should have the correct 'after_install' trigger script
* rspec ./spec/fpm/package/rpm_spec.rb:270 # FPM::Package::RPM#output package attributes should have the correct 'before_install' trigger script