typo fixed: JSON.stingify => JSON.stringify
Merge pull request #78 from d3lity/patch-1

typo fixed: JSON.stingify => JSON.stringify
Merge branch 'master' into develop
Dropped support for IE8 (was already broken). Improved error message for unsupported browsers.
Cleaned up legacy code for IE8
Fixed blocking of mouse scroll when context menu is visible
Disabled saving files using HTML5 on Firefox to prevent a Firefox bug