Updated website after changes to Grouping calculated property names

Sum => sum
Total => total
Average => mean
Count => count
Updated docs for Dimension and Grouping
Updated change log
Updated website after Grouping documentation updates
Fixed mistakes in change log
Replaced total with totalCount in result of counting Grouping properties
adding theme demo page
Merge pull request #261 from niksoper/gh-pages-dev-review-groupings

Updated website after review of groupings
updated the href in tables demo to point to the docs without the localhost prefix.
Merge branch 'gh-pages-dev' of https://github.com/ScottLogic/insight into feature/add-theme-demo
updating the insight library zip
updating the theme demo to prevent a potential race condition
Merge pull request #265 from seanworkcode/feature/add-theme-demo

adding theme demo page
Updated getting started page

in response to pull request comments
Merge pull request #262 from tylerferguson/feature/getting-started-page

Created and added content to Getting Started page
Merge remote-tracking branch 'upstream/gh-pages-dev' into web-feature/structure-review

Conflicts:
	js/controllers/explorerController.js
	js/insightChartsControllers.js