Build: Fix demo asset copying

- Don't copy SCSS files to unmin
- Use better scope for copying umnin assets to minfied

Fixes gh-3867
Build: Fix CSS minification targets

Previously the CSS was copied from unmin and left an extra unminified
copy after minification.
Merge pull request #3871 from nschonni/v4-fix-demo-asset-copying

Build: fix demo asset copying and minification
v4 Tabs (and carousel) fixes. Fixed misnamed sass file. Changed Prev/Next/Tab click behaviour. Now the carousel stops if any tab or control is pressed, except Play, as requested by @num3thod.
Added init event to all plugins and polyfills to support manual (non-timerpoke) initialization
Merge pull request #3875 from pjackson28/addediniteventhandling

Added init event to all plugins and polyfills to support manual (non-timerpoke) initialization
Added fixes suggested in pr #3874.
Session timeout: Cleaned up timeout issue with Mocha test
Events calendar: Removed console statement
Merge pull request #3881 from pjackson28/cleanuptest

Session timeout: Cleaned up timeout issue with Mocha test
Merge pull request #3874 from schindld/v4-carousel-fixes

v4 Tabs (and carousel) fixes.