Update grid.addons.js

solve issue when use grid.addon and the operators is showing with "Object Object"
Update grid.addons.js

solve issue when use grid.addon and the operators is showing with "Object Object"
Merge pull request #586 from claytonsilva/patch-2

Update grid.addons.js
Merge pull request #585 from claytonsilva/patch-1

Update grid.addons.js