Build: Collapse targets that aren't called alone

Sass and autoprefixer never call the subtargets, so moved globs to "all"
target array
Build: Create demos targets

- Combine several copy targets to simplify demo asset copying
Build: Fix imagemin globbing

- src and dest must match for inplace minification to work
- remove "min" target because minified images are copied already from
unmin now
Build: Collapse JS copy targets
Merge pull request #3832 from nschonni/v4-cleanup-globbing

V4 cleanup globbing