Fix "Cannot find stylesheet" error on GoogleChrome

Signed-off-by: Saulo Castelo Sampaio <saulocastelo@gmail.com>
Fix "Cannot find stylesheet" error on GoogleChrome

Signed-off-by: Saulo Castelo Sampaio <saulocastelo@gmail.com>
Merge branch 'master' of github.com:saulocastelo/SlickGrid

Signed-off-by: Saulo Castelo Sampaio <saulocastelo@gmail.com>

Conflicts:
	slick.grid.js
Fix for calling setColumns during edit does not work

When calling setColumns() while a cell is being edited, weird things
happen.
Remove duplicate results from getAllStyleSheets
Merge remote-tracking branch 'remotes/csgsolutions/master' into k0stya-rowspan

Conflicts:
	slick.grid.js
Merge remote-tracking branch 'remotes/saulocastelo/master' into k0stya-rowspan -- thus marked as inspected; borrowed part of the solution as the existing code already worked for most.

Conflicts:
	slick.grid.js