v0.8.0

• Parse command line arguments with optparse. Remove dependency on Slop.
  Simplified commands DSL: options are mostly passed directly to optparse.
• search.relative_roots default changed from from %w(app/views) to
  %w(app/views app/controllers app/helpers app/presenters).
• add-missing now adds keys detected in source to all locales (previously just base) #134.
• The default spec template no long requires spec_helper by default Daniel Levenson #135.
• search.exclude now appends to and not overrides the default exclude list. More extensions excluded by default:
  *.css, *.sass, *.scss, *.less, *.yml, and *.json. #137.