JASPA: Change properties handling code.

There are several reasons why properties within the Java Agent need to be reworked:

• Property names are inconsistent with the C Agent
• Some properties just aren't used anymore, even though they are referenced in the codebase
• The original property names don't follow any logical naming rules and don't even share the same base
• Some old property names are practically meaningless
• Some new property names have been badly chosen
• Property initialisation is a nightmare for the unit tests, thus no unit test can access properties
• Property handling uses deprecated classes from the Client SDK
• Backwards compatibility must be maintained
• Property name changes have implications for the XUI
• Need to sort out which properties are hot-swappable and which are not
• The documentation team are constantly complaining that Java Agent properties are a mess

Here are some examples of the inconsistencies. All of these are properties used by the agent:

com.sun.identity.sm.cacheTime
com.iplanet.am.cookie.name
com.iplanet.services.debug.level
com.sun.identity.agents.config.session.attribute.mapping
com.iplanet.am.session.client.polling.enable
org.forgerock.openam.sdk.com.sun.services.debug.mergeall
org.forgerock.openam.agents.config.policy.evaluation.realm

In order to reconcile old/existing names with new/rational ones, I propose inventing "aliases" for property names. Thus it will be possible for a single property value to go by two (or more) distinct names. For example:

com.sun.identity.sm.cacheTime
org.forgerock.agents.cache.timeout.milliseconds

This will pave the way for more sensible, consistent and descriptive property names while still maintaining backwards compatibility. It does pave the way for problems where a customer sets the same property via two (or more) different names to different values. Perhaps a warning should be issued if this is the case. I propose "rational" property names start with the root:
org.forgerock.agents

just because it is shorter than one of the new variants, which is:
org.forgerock.openam.agents

I also propose dropping the word config from everywhere in all properties. It's a property, what else could it possibly be but configuration?