* UX: make composer resize work on touch devices
This also replaces a vendor dependency with a small built-in resize mechanism.
* Make blue bar's larger padding specific to touch devices
This commit also:
- removes [+ New Topic] behaviour from share, this feature has been duplicated in composer actions, months ago
- introduces our new experimental spacing standard for css: eg: `s(2)`
- introduces a new panel UI for modals
If a theme setting contained invalid SCSS, it would cause an error 500 on the site, with no way to recover. This commit stops loading theme settings in the core stylesheets, and instead only loads the color scheme variables. This change also makes `common/foundation/variables.scss` available to themes without an explicit import.
- These advanced fields are hidden behind an 'advanced' button, so will not affect normal use
- The editor has been refactored into a component, and styling cleaned up so menu items do not overlap on small screens
- Styling has been added to indicate which fields are in use for a theme
- Icons have been added to identify which fields have errors
New `about.json` fields (all optional):
- `authors`: An arbitrary string describing the theme authors
- `theme_version`: An arbitrary string describing the theme version
- `minimum_discourse_version`: Theme will be auto-disabled for lower versions. Must be a valid version descriptor.
- `maximum_discourse_version`: Theme will be auto-disabled for lower versions. Must be a valid version descriptor.
A localized description for a theme can be provided in the language files under the `theme_metadata.description` key
The admin UI has been re-arranged to display this new information, and give more prominence to the remote theme options.
