Bug 957894 - Pre: Remove outdated comment.
Bug 957894 - Part 1: Add fxa account pickling code.
FOLD: Correct KEY_ACCOUNT_VERSION value.
FOLD: Remove unnecessary TODOs.
FOLD: Correct FileOutputStream cleanup.
FOLD: Add non-existant account assumption to unpickle javadoc.
FOLD: Remove unnecessary comment.
FOLD: Add reminder comment about updating the account.
FOLD: Add Bundle docs.
FOLD: Add account version to addAccount code.
FOLD: Add Bundle to addAccount params.
FOLD: Fix AccountPickler bugs.
FOLD: Fix Eclipse warnings.
Bug 957894 - Part 2: Test AccountPickler.
Bug 957894 - Part 3: Pickle on sync.
Bug 957894 - Part 4: Unpickle in accountsExist.
FOLD: Fix m-c build error.