Replace FileSystem API with chrome.storage.local

[gorhill]

Because http://code.google.com/p/chromium/issues/detail?id=389879.

Apparently The QUOTA_BYTES "value will be ignored if the extension has the unlimitedStorage permission" (ref)

I can't tell whether Chromium 37 will break HTTPSB, uBlock, (Adblock Plus, etc). Nowhere can I find feedback about this from Chromium devs. Given that FileSystem API has been dropped as candidate technology for HTML5, I will assume the worst and try to find an alternative.

Not sure if chrome.storage.local will work, I have to write prototype code.

[rusvnc]

Please keep us posted. Thanks.

[gorhill]

chrome.storage.local does work, so I am converting the code. It's actually simpler, I wish I had done it this way the first time. The only complicated bit is to ensure users' data is properly transferred to the new storage.