Improving Options with better construction via properties

[scottf]

• Allow creation of connections requiring an AuthHandler for JWT to specify the credentials file in a properties files, instead of needing to provide an instance of AuthHandler in code.
• Allow creation of connections requiring an SSL context to specify key and trust store information in a properties files so an SSLContext can be created automatically instead of needing to provide an instance of an SSLContext in code.
• Support properties keys with or without the prefix 'io.nats.client.'

Property	Description
credential.path	Used to set the path to a credentials file to be used in a FileAuthHandler
keyStore	Property for the keystore path used to create an SSLContext
trustStore	Property for the truststore path used to create an SSLContext
keyStorePassword	Property for the keystore password used to create an SSLContext
trustStorePassword	Property for the truststore password used to create an SSLContext
tls.algorithm	Property for the algorithm used to create an SSLContext

[ColinSullivan1]

Looks good, really like the per-connection properties here. A minor suggestion would be the ability to build the with options and override. E.g. to set the props file in the builder via method and also be able to set a name, reconnect tries, etc. Best of both worlds.

[RichardHightower]

Docs added to the readme would be swell. :)

[scottf]

A minor suggestion would be the ability to build the with options and override.

I've added a builder setter to take properties. When it comes to the builder, the last one called wins.

// last one wins
props.setProperty(Options.PROP_MAX_MESSAGES_IN_OUTGOING_QUEUE, "500");
o = new Options.Builder(props)
    .maxMessagesInOutgoingQueue(1000)
    .build();
assertEquals(1000, o.getMaxMessagesInOutgoingQueue());

o = new Options.Builder()
    .maxMessagesInOutgoingQueue(1000)
    .properties(props)
    .build();
assertEquals(500, o.getMaxMessagesInOutgoingQueue());