I implemented LiteralValue Nils for LengthKinds: Delimited, Pattern, and Explicit. Explicit only works for LengthUnits.Bytes and LengthUnits.Characters at the moment. All others should error with "Not Yet Implemented".

LengthKind.Implicit is not allowed for representation='text', unless it is a complex type. So this will eventually throw an SDE (Schema Definition Error). However, LiteralValue nil is generally unimplemented for LengthKind.Implicit right now.

LiteralValue Nils are not valid unless it's representation='text'. Representation='binary' for LiteralValue nils will now throw an SDE.

The affected tests are located in daffodil-test/src/test/scala/daffodil/section13/nillable/TestNillable.scala.

Tests: test_binary_01, test_entity_fail_05, test_entity_fail_06.

These tests were commented out from the 'live' section and moved to the 'debug' section pending alteration.

Commits: 1519d3, a934f3, 602a78