move creation of true/false/nil option to option_parser
added markers to readme to update worker options using script
script/options_for_readme => script/update_worker_options_in_readme
updated default for jpegtran jpegrescan option in readme
hash_helpers
moved code from bin/image_optim to ImageOptim::Runner
Merge branch 'refactor'
require rspec in all specs
separate files for BinNotFoundError, ConfigurationError and TrueFalseNil classes, require only needed files instead of image_optim
don't use Jhead in config_spec
Merge branch 'refactor'
fixed Abc worker in config spec
Merge branch 'refactor'
removed wrong versions rbx-18mode and rbx-19mode
require fspath v2.1.0 with fixes for jruby 1.7.8
don't allow failures with jruby
Merge branch 'master' into rails

Conflicts:
	image_optim.gemspec