Summary:
Unlike non-sandy plugins, non-sandy plugins weren't serialized using our serialization utility yet. This diff addresses that, meaning that users don't have to bother about how to serialize maps, sets and dates.
Unlike the old fashioned plugins, the `makeObjectSerialize` utility is used, rather than `serialize`. This normalizes the objects, but doesn't serialize them, which is done at the end of the export data process anyway for the whole tree. This avoids creating a double JSON serialization which is fully of ugly escape characters.
This makes the onImport / onExport definition of the logs plugin nicer.
Also improved the docs.
Reviewed By: nikoant
Differential Revision: D26146421
fbshipit-source-id: 6abfb6ee2e3312e2a13a11832ff103dc62fd844c