[FeatureRequest] Cloud Storage: There can be only One!

[Bartolomeus-649]

The feature to store settings in the cloud is good!
But there are some stuff that need to be fixed for it to be really great.

1. There should be one, and only one place where settings are stored. To have separate storage based on who happened to deliver the current browser I'm using is not very user friendly or intuitive.

2. A user should be able to configure which (cloud) store to use. I put cloud in parenthesis because a user might want to specify a local path. Remember, there are a lot of different systems out there, everything from Windows Roaming Profiles, Windows To Go and DropBox to OneDrive, SharePoint and Google Drive.

3. Implement a provider model for saving settings, so anyone can write a plugin that conforms to a specified interface, and get their custom solution to work, whatever it might be.

4. Implement a solution for the most simple and basic scenarios: Add two EditBoxes...
   a) Add an EditBox where a user can write a "SaveSettings" JavaScript function that is called whenever settings need saving. The function is called with one string parameter that should be saved in any way the user wants.

   b) Add a seconed EditBox where the user can write the "LoadSettings" function, which reads the settings and just return them.

   c) To make things simple the the parameter/return-value should be a string, so there is no need of any data processing what so ever by the script.

5. Document where the settings are stored internally. So it would be possible to use an external tool/utility to sync/store the settings wherever the user wants.

6. Implement an API to get and set settings, or at least to tell the AddOn that the settings has been updated so it can re-read them.