mutate() original state / source restoration improvements

• Should restoration only work on remember (name pending, maybe recall) class/attrib elements?

WeakMap (node as key)

• Removes need for ID, uses node itself as key
• 👍 Allows for garbage collection
• ❔ Enforces 1:1 original source ID
• ❌ DOM.reset less performant (have to WeakMap.get all potential elements)

Data attribute + array

• 👍 Super fast reset via querySelectorAll('[data-osid]') reference
• ❔ Allows for 'duplication' of OS content by copying OSID references
• ❌ No cleanup if element is permanently removed
• ❌ Dirtys DOM (see #103)

DOM node property + array

• 👍 Does not dirty visible DOM
• ❌ Chance of prop collision (but low due to pd_ naming convention)

Misc

• Rename OSID if appropriate.
  • renamed to originalState
• Rename to initialStateif we don't allow replacement of original?