Fix for Coco 0.7.6, path.exist -> fs.exist. New Dust engine.

[rektide]

Hi there. Sorry, I didn't know pull requests off a single branch would have such poor granularity: I would've done feature branches had I known. The changes are all very small, mercifully & safe.

The first two commits address Coco 0.7.6 removing + as an Array concatenator. The issue for that is: https://github.com/dsc/connect-compiler/issues/7 https://github.com/rektide/connect-compiler/commit/f96dbbe4b573369a649a8372f15c91da3d2eabd5

The third commit implements (fs.exists || path.exists) to handle node's migration of this API item. The issue for that is: https://github.com/dsc/connect-compiler/pull/6 You are correct in your assesment: https://github.com/dsc/connect-compiler/pull/6#issuecomment-6875554 https://github.com/rektide/connect-compiler/commit/57ca095a16cb5e58f684a30c4a9f1d612d9e5083

The fourth commit is a feature, support for compiling Dust.js templates. This will work with nearly any dust version, but the best maintained atm is LinkedIn's. The issue for this is: https://github.com/dsc/connect-compiler/issues/8 https://github.com/rektide/connect-compiler/commit/206c35b4693f4a91449ccea9d91336fdcb89424b

Thank you very much for developing and maintaining this epic library. If I can assist you with any of these issues, please let me know how I can help.