Concurrency problem
It looks like it is not possible to lock the entry when wanted to change its value.
What do you think to implement something like https://bitbucket.org/balpha/lockablestorage/src/96b7ddb1962334cde9c647663d0053ab640ec5a1/lockablestorage.js?at=default ?
See http://balpha.de/2012/03/javascript-concurrency-and-locking-the-html5-localstorage/ .
It is a good idea, but not easy to do because objective of this plugin is to not use local storage as a simple key/value storage but as a hierachical object. So be able to lock a part of this object is more complicated. It's like the issue #11, functionnality is a good idea but not easy to do. Unfortnuattely, I have no time to work on this kind of functionnalities now. But if you have time, I can check your changes and perhaps include it ;)
Perhaps locking the entire key/value storage would be ok too.