copy global load path from sass

[michaelglass]

adding support for SassC.load_paths and SASS_PATH to make it easier to migrate from Sass to SassC

[borama]

Just a context note: this will be a very welcome addition. After migrating to sassc, we have problems with slim-lint (the linter for the Slim templates), which cannot deal with relative SASS imports (@import 'lib/somefile') used in SASS blocks embedded in Slim templates any more. There is currently no way for the SASS load paths to be specified in slim-lint.

Before upgrading, we used the SASS_PATH env variable to globally set the SASS load path before running slim-lint and everything worked without issues, as this was supported in the sass-ruby gem itself. The same support would be very nice in sassc, too. Currently, we are trying the forked version with this PR merged, and all seems to work again nicely.

[bolandrm]

Thanks!