Smarter approach for getMatchingRules

Also replaced a "if ... or ... or ... " cascade with a switch statement
Compile the stack to a javascript function
Cache the index/position of the MOM Node in its parent.

Instead of linearly seaching for it on every request.
ParameterDict: make an index on first access.

Instead of a search each time.
StyleDict/ReferenceDict: make an index on first access.

Instead of a search each time.
Also introduce a common parent class for StyleDict and ReferenceDict.
use ExportController.es6.js directly in browsers
Selectively picking the ES6-Proxy upgrade
Merge pull request #308 from graphicore/collected-performance-improvements

Collected performance improvements