Copied the constructor jsDoc to all classes
I guess the license refers not just to the documentation?
Use the new mechanism for the callback functions
Added documentation to DataSources.getSources
Added documentation to ConceptWikiSearch .byTag() and .freeText()
Also make limit and branch optional for byTag(), just like with freeText()
If not mistaken, there was a null too much in the documentation
Merge remote-tracking branch 'egonw/feature-master/jsDoc' into ian_egonw_jsdoc

Conflicts:
	src/DataSources.js
latest combined file with improved docs