Initial Digest Authentication work

Added check of WWW-Authenticate header for required security method
Added code to generate a Digest response for the Authentication header
Added utility code around the above.
Added support for persisting authentication requirements between requests (E.g. nc value)
Fixed type bug in split call
Merge pull request #540 from adamfowleruk/master

Fix for issue #538
Fixed digest issues - invalid URLs and lower case of hex values of hashes

Confirmed working against MarkLogic REST server with Digest
authentication
Fix commit for webrequestutils
Removed debugging log statements, added some comments
Merge pull request #542 from adamfowleruk/master

Completed fix for issue #538
Add new redis LInsert operation to interfaces
GetParam should not fail when name is null
Merge remote-tracking branch 'upstream/master'