Verbatim-safe typography, ^-punctuation quoting, full-range ^UUUU^, polyglot html

Typographic transforms (---, quote pairs, ~) no longer touch verbatim
text: @c/@code/@source_listing content and ^'...'^ spans show exactly the
characters written. "^" before any punctuation character quotes it in
every target (the apostrophe excepted: ^' opens a literal span), with the
new :resolve option on @@@target declaring per-target renderings. The
^UUUU^ code-point form accepts 4-6 hex digits, the full Unicode range.
The html output and transform spellings are polyglot (XML-valid), in
preparation for an EPUB target. New suites: transform_test, character_test
(engine), typography_test (SKS).

(from dev 07ce5ea86a0a)

mac/target_registry.h

@@ -51,7 +51,7 @@ public:
 
 
     /*
-    std::string m_parameters_spec {"name | desc :after_apply :after_write :includes | transforms.rest"};
+    std::string m_parameters_spec {"name | desc :after_apply :after_write :includes :escape :resolve | transforms.rest"};
     Parameter_set m_parameters =
         katomize(line_split(m_parameters_spec), Locator().str());
     */