NumberElement > RangeElement
Use unpinned library when inlining.
Fix RangeElement text_content parsing.

Handle text_content not matching the parsing pattern (that provides a default value and display precision). Return correct default value if none were parsed.
Add debug option for using unminified libraries.
Update lib url to new GitHub pages domain.
Add is_dragging flag to DragManager.

This will allow elements to defer expensive or disrupting operations while the user is interacting with the document, if necessary.