finLogRO Business Layer object; optimised DocumentHtml functions

DocumentHtml functions in the finLogRO Business Layer object have been optimised.

There is now a "HasDocumentHtml" property which returns True if there is a value in DocumentHtml. If False the DocumentHtml and other methods no longer do any work, such as attempting to load the DocumentHtml.

Note, in addition the property BranchPk has been obsoleted.