option('warnings', type: 'combo', choices : ['no', 'min', 'max', 'fatal'], value : 'fatal',
  description : 'Compiler warning level')
option('build-examples', type: 'boolean', value: false,
  description : 'Build all example programs')
option('validation', type: 'boolean', value: true,
  description : 'Validate the untranslated XML file')
option('build-translations', type: 'boolean', value: true,
  description : 'Build translated tutorials (built during installation)')
option('build-pdf', type: 'boolean', value: false,
  description : 'Build tutorial PDF file')
