Automatically strip `debug` in production

A bunch of small changes to reduce overall bundle size, which ultimately impacted backward compatibility.

Changed

• Remove IS_UNIQUE and DISPLAY_NAME exports in favor of $unique and $displayName keys
• Remove debug support in favor of process.env.NODE_ENV
  • This enables code stripping in production for Webpack and other bundlers and resulted in a 0.6kB bundle size reduction
• Remove hash function customization
  • As far as I know no one has used it in production and it increases scope of the package (let me know if you are!)

DISPLAY_NAME style tags

Added

• Support DISPLAY_NAME on style objects
• Ignore any keys starting with an _

Reduce object creations during stylize

Changed

• Reduce one object creation per nested level of styles during stylization to internal object representation

Styles that fire together wire together

Added

• Keep styles that are registered at the same time together instead of de-duping
  • This should result in a more consistent cache order (based on first insertion instead of last), no re-ordering and no de-duping of partially registered styles

Expose `Cache#values`

Added

• Expose a function to get the list of values in the current cache ordered as it would be in the sheet output

CSS Numeric Properties

Added

• Add more CSS numeric properties to whitelist

Fix Overloaded Property Ordering

Fixed

• When a property has > 10 overloads, Chrome has an undefined sorting order for matching elements (good breakdown in #66)

Escape Display Name

Changed

• Escape the display name in output CSS for special character support in class names

Minor Bump

Improved

• Custom string concatenation is faster than Array#join for the perf tests
• Update hyphenate regexp matching to do less work

Speed-Up

Improved

• Internally manage styles via an array of strings instead of computing getStyles() on demand
• Switch to Object.create(null) for cache maps