B-48882 - Archiving: Hadoop Adapter for Retrieval of Archived Events

To support archive adapters I added the following:

-	Expanded FeedSource interface to declare the “current” link URL for archived feeds.
-	Expanded FeedSource interface to declare the “next-archive” link URL for feeds which have archived feeds.
-	Added AdapterHelper class to handle archive-related logic for adapters.
-	Expanded atom-server.cfg.xml format to allow archive-feed & current-feed which are used to declare links between current feeds & archived feeds.
-	Updated regression paging.jmx regression test to verify interface between current feeds & archived feeds as well as verifying the archived feeds prev-archive & next-archive links.
B-48882 - Archiving: Hadoop Adapter for Retrieval of Archived Events

To support archive adapters I added the following:

-	Expanded FeedSource interface to declare the “current” link URL for archived feeds.
-	Expanded FeedSource interface to declare the “next-archive” link URL for feeds which have archived feeds.
-	Added AdapterHelper class to handle archive-related logic for adapters.
-	Expanded atom-server.cfg.xml format to allow archive-feed & current-feed which are used to declare links between current feeds & archived feeds.
-	Updated regression paging.jmx regression test to verify interface between current feeds & archived feeds as well as verifying the archived feeds prev-archive & next-archive links.
Merge branch 'B-48882_archive' of https://github.com/usnavi/atom-hopper into B-48882_archive

Conflicts:
	tests/regression/src/test/jmeter/paging.jmx
- Adding more unit tests for adapters for archive feeds
- Updating method name to FeedSource.setCurrentUrl()
- MigrationFeedSource.setCurrentUrl() set to no-op
- Added WorkspaceConfigProcessorTest
Merge pull request #260 from usnavi/B-48882_archive

B-48882 - Archived Feeds: provide next-archive, prev-archive links, per RFC 5005