Bug 955808 - Pre: Add ExtendedJSONObject.getBoolean.
Bug 955808 - Pre: Add ExtendedJSONObject.throwIfFieldsMissingOrMisTyped.
Bug 955808 - Pre: Use ExtendedJSONObject methods in TokenServerClient.
Bug 955808 - Part 1: Add pure Java PBKDF2 implementation.
Bug 955808 - Part 2: Update FxAccountUtils.generate* for "onepw" protocol.
Bug 955808 - Part 3: Add FxAccountClient20 that speaks "onepw" protocol.
Bug 955808 - Part 4: Add FxAccountClient.status method.
Bug 955808 - Post: Point to https://api-accounts-onepw.dev.lcip.org.
Bug 955808 - Implement Android Firefox Account client that speaks "onepw" protocol. r=rnewman