XSB Src (SVN)-old

Cleaned up some very obscure code on passing file names to load_object_file.

Added a def for use with incrementa, abstract

Now supporting incremental, abstract(0)

took out unused export.

test for incremental, abstract(0)

Clean up load_object_file, motivated by handline immutable better.

To simplify communication of not-loaded due to immutable file back to loader.P.

Removed a spurious character.

Factored the code for lazy incremental recomputation out into a function so I can reuse it for call subsumption.

Fixed immutable, which I had broken (as side effect added some error messages when loading failed where previously it was silent). Added error checks for some multifile anomalies.