remove duplicate case

remove duplicate case "ol"
Merge pull request #115 from hyaocuk/patch-1

remove duplicate case
fix typo
Merge pull request #116 from hyaocuk/patch-1

fix typo
fix for IE10/IE11
Merge pull request #117 from teambition/master

fix for IE10/IE11
add `insertimage`, fixed #118
remove unnessary codes
improve placeholder, fix bug for range
Merge pull request #119 from teambition/master

improve placeholder, fix bug for range