FIX: Multiple pattern parameters down a render tree cause issues

[bmuenzenmeyer]

part of resolution for pattern-lab/starterkit-mustache-acidtest#1

Addresses #539

Summary of changes:

• Found pattern parameters retrieve the partial, of course, but that returned partial itself needs to check for pattern parameters.
• I think now Node functionality is more on spec of individual patterns being independentally rendered, downstream.

[coveralls]

Coverage increased (+0.01%) to 71.511% when pulling 5998c9c on issue/539-chained-parameters into 1f456d2 on dev.

[coveralls]

Coverage increased (+0.01%) to 71.511% when pulling 5998c9c on issue/539-chained-parameters into 1f456d2 on dev.