v15.1.3

What's Changed

• enhance: Use injection factory for NG_SCROLLBAR_OPTIONS and NG_SCROLLBAR_POLYFILL to avoid merging custom options with the default options for every scrollbar component.
• refactor: Use self option when injecting NgScrollbar component in all addon directives.
• fix: Scrollbar with externalViewport attached scrollbar not destroyed properly causing memory leak, closes #611.

Full Changelog: v15.1.2...v15.1.3