Implement the replacement-text constraint at the point of reference: when a
general entity is included, its replacement (character references expanded
as at declaration time) must reparse as balanced content in isolation, via a
new EntityReplacementGrammar mini-parser. This rejects a bare or incomplete
reference ('&', '	' unterminated), tags spanning the entity boundary
('</foo><foo>'), a raw '<' or incomplete reference inside an embedded
attribute value, '<' followed by a non-name character, and a reserved-target
PI in the replacement, exactly the suite's semantics, including that an
UNREFERENCED entity may carry any value and that only the first declaration
of a name binds. Attribute-list defaults must reference already-declared
internal (not external/unparsed/forward-declared) entities with a
non-recursive chain. A CDATA section inside replacement text now shields its
content from reference expansion, fixing the last valid-side case.
W3C xmltest final standing: valid/sa 119/119, not-wf/sa 180/186, with the
six remaining deviations all deliberate and documented in the baseline:
internal-subset conditional/CDATA sections (063, 107) and parameter-entity
references (160-162) are features this package supports, and 141 expects the
1998 suite's name-character classes where this package implements XML 1.0
Fifth Edition's. Zero false positives across all 846 tests at every step.
Closes#120