[BZ 1069547]  Support EAP 6.2/6.3 style patching STAGE 1

This is the first from a series of 3 PRs to support EAP-style patching in RHQ.

This PR sets the stage for the new bundle type and the associated agent-side bundle handler.
It introduces the following changes:

1. New type of bundle destination called "location", which is not supplied by merely a "base-dir" but by a more complex "connectionString", which is an expression with Wildfly-style property references, i.e. "http://${host:localhost}/asdfdf", as well as references to other configuration properties or traits.
2. The deployDir attribute of the bundle destination is made optional, because it is not meaningful for all types of bundle handlers (well, it does not make sense for at least the to-be-reviewed patch bundle handler).
3. Bundles no longer have to be backed by files (the reasoning for this in the commit message of 3841c3e, again something that is related to the patch bundle handler).

Once this is reviewed and deemed OK, I will either add the commits to this PR or we can merge this PR first and I'll open a new PR with the new commits after that (possibly that'd be better just to make the PRs smaller).