This commit promisifies following APIs:
BaseViewer#importXML
BaseViewer#importDefinitions
BaseViewer#open
BaseViewer#saveXML
BaseViewer#saveSVG
Modeler#createDiagram
Related to https://github.com/bpmn-io/bpmn-js/issues/812
BREAKING CHANGES:
* Users are now expected to have Promises either by default or
polyfilled as the APIs return a Promise now.
* use ES6 import / export
* UTILS: export individual utilities
* TESTS: localize TestHelper includes
BREAKING CHANGE:
* all utilities export independent functions
* library sources got ported to ES6. You must now use
a ES module bundler such as Browserify + babelify or
Webpack to consume this library (or parts of it).
Async utilities properly propagate _all_ errors to the
specified _done_ callback. Failing in _done_ does not
re-invoke it.
Adjustments made in
* Viewer#importXML
* Viewer#saveSVG
* Importer#importBpmnDiagram
Tests cleaned up to remove un-necessary `if (err) { ...` snippets.
This commit ensures we correctly detect and import
Data*Associations and Associations.
It aligns logging across the import components, too, being slightly more
verbose and helpful.
Related to #112