* Import @action rather than using actions: {}
* Set default values in functions outside of init, so the functions can be modified by modifyClass (plugin api).
* Move padding from .choices div to the input in group selector.
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
