Escaping, table layout, and document fixes

Quoted Klammertext specials (^@ ^| ^# ^^ ^: ^*) and ^'...'^ regions now
survive re-processing (held as escape markers until final output);
:after_apply phase functions receive and return raw target text.

Tables: :hpos element position (center|left|right|<length>) replaces the
unimplemented :center/:indent; the ranged cell override is renamed
:justify; :column_width works in html (colgroup widths) and gains
'fill' -- the remaining width, capped at the column's widest entry, in
both targets; a table wider than the text column warns on the console;
table edges without an outer line set their text flush on the margins.

@document: no empty title bar for untitled documents; @vfill fills to
the bottom of the window in html (pure CSS); @vspace in plain text;
new @dot klammer; monospace email links.

mac/eval_python.cpp

@@ -29,6 +29,16 @@ Eval_python::Eval_python(Machine& machine, Locator loc)
     m_globals = PyDict_New();
     m_locals = PyDict_New();
     PyDict_SetItemString(m_globals, "__builtins__", PyEval_GetBuiltins());
+    // The machine's result text, so :after_apply phase functions can take it
+    // as an argument (the Python counterpart of a :cpp phase function reading
+    // machine.m_result). Set directly rather than through the state's
+    // python_code() because document text cannot be safely embedded in a
+    // quoted Python source string.
+    PyObject* result_text = PyUnicode_FromString(m_machine.m_result.c_str());
+    if (result_text) {
+        PyDict_SetItemString(m_globals, "K_result", result_text);
+        Py_DECREF(result_text);
+    }
     import_module("inspect", false);
     if (!m_machine.m_state.m_frames.empty()) {
         PyRun_String(m_machine.m_state.python_code().c_str(), Py_file_input, m_globals, m_locals);