fix IE11's false positive number support with checkValidity
Merge pull request #1405 from patrickkettner/fix-ie11-number

fix IE11's false positive number support with checkValidity
improve grammer in readme
Merge pull request #1424 from janroures/master

improve grammer in readme
Merge pull request #1423 from anenviousguest/master

More IE7 fixes: atRule and unit test