Fix setEncryption issue for multiple client.

PR #6 | Move encryption to Hoa\Socket\Node

PR #6 | Fix erase declaration

PR #6 Rename encryption to encrypted

PR #6 | Rename function & change default flag type to null

PR #6 | Fix enableEncryption()

PR #6 | Fix rename property

PR #6 | Rename Connection::getEncryption() to getEncryptionType()

PR #6 | fix null instead false

PR #6 | Optimize Connection::enableEncryption

PR #6 | Rename Connection::getEncryptionType into Connection::isEncrypted

PR #6 | Fix null equal & reinsert in if/else condition

PR #6 Fix minor syntax write
Fix CS and API documentation.
Update comment of Node::setEncryptionType()