Feature/upgrade handsontable

This pull request upgrades Handsontable to v0.9.5, including 2 results from hackathon:

1) Fix a Bootstrap integration issue that cut the cell content: http://scr.hu/0cbq/iahtk
2) Choose column type in the column header dropdown. When new column type is chosen, cells are revalidated: http://handsontable.com/demo/renderers_html.html (scroll to bottom for the demo)

I smoke tested page "Check & Describe" screen after the upgrade. Seems to work as fine as before :)