security: Added MemoryPrivateKeyStorage, SelfVerifyPolicyManager, IdentityManager and KeyChain.
tests: Added node/test-encode-decode-data.
tests: In browser/test-encode-decode-data, use a KeyChain instead of the deprecated data.sign().
security (minor): Remove an incorrect comment (Exclude) from the new security files.
Merge remote-tracking branch 'upstream/master' into chrono-sync2013