Added PHPStorm project files to .gitignore
Cleanuped code for enforced cookie usage

In my last pull request I added the first support for handling of the enforced usage of cookies as storage. Now I added this support to the remove function and to the clearAll function. Also I exluded warnings that the browser does not support local storage if the user explicitely wants to use cookies.
Merge pull request #119 from FeelgoodDE/master

Cleanuped code for enforced cookie usage