User Alert Library

Version 1.1.0 posted - taking notes from CI4's Pager class the Alerts library can now accept a renderer (or will fallback to default renderer service) and use that to return formatted template HTML/CSS. It doesn't look like anyone is using this, but notable change (hence 1.1.0 instead of 1.0.1) is the wrapping helper functions should now be output rather than simply called:
`alerts()` -> `echo alerts()`

Thanks for the suggestion @PaulD! I'll be making this same update to the Assets library as well.