Lemon updates: (1) include the #defines for all tokens in the generated C

file, so that the C-file can be stand-alone.  (2) If the grammar begins with
a %include {...} directive on line one, make that directive the header for
the generated C file.  (3) Enhance the lemon.html documentation.

FossilOrigin-Name: 84d54eb35716174195ee7e5ac846f47308e5dbb0056e8ff568daa133860bab74

src/parse.y

@@ -1,5 +1,6 @@
+%include {
 /*
-** 2001 September 15
+** 2001-09-15
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -9,11 +10,16 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file contains SQLite's grammar for SQL.  Process this file
-** using the lemon parser generator to generate C code that runs
-** the parser.  Lemon will also generate a header file containing
-** numeric codes for all of the tokens.
+** This file contains SQLite's SQL parser.
+**
+** The canonical source code to this file ("parse.y") is a Lemon grammar 
+** file that specifies the input grammar and actions to take while parsing.
+** That input file is processed by Lemon to generate a C-language 
+** implementation of a parser for the given grammer.  You might be reading
+** this comment as part of the translated C-code.  Edits should be made
+** to the original parse.y sources.
 */
+}
 
 // All token codes are small integers with #defines that begin with "TK_"
 %token_prefix TK_