Using @constructor rather than @class

@constructor and @class are synonyms and @constructor is a better fit
because there is technically no such thing as a class in JS
Renamed files to match lowercase convention
Renamed insight.Constants => insight.constants
Renamed insight.Utils => insight.utils
Updated Constants => constants, after merging from upstream
Updated @class to @constructor after review
Merge branch 'develop' of https://github.com/ScottLogic/insight into develop

Conflicts:
	Changelog.txt
	src/mda/DataSet.js
	src/mda/Dimension.js
	src/mda/Grouping.js
Updated @memberof! insight.Axis to insight.Table
Merge pull request #247 from niksoper/develop

Fixed Table documentation