refactor plugin logic, add import support
fix import logic
ocd
update rework-vars to 3.0.0, remove myth.js
ocd
readd browser support, ffs
1.0.0

* add `@import` support
* add support for new CSS variables syntax
* add `compress` option
* add `browsers` option
Merge branch 'master' of github.com:segmentio/myth