Big bugfix diff for tidy26sep99

Here's that big diff I promised for last night.  (Some delays due to 
net inaccessibility when I needed it.)  The changes are:

  * New defines for HTML 4.01 DTD support (still indistinguishable from 4.0 but
    is now a solid groundwork).
  * Using wstrcasecmp to match attribute names and tag names instead of
    wstrcmp, just to be safe.
  * Added new configuration option always-quote-attrs which defaults to yes.
    XML output forces this to yes.  If no, won't put quotes around attribute
    values that don't require them.
  * Rearranged the struct _node so that *content is between *prev and *next,
    which makes it a little easier to navigate the structure in debuggers.
  * Added new tests and error messages for use of multiple TITLEs, BASEs,
     and ISINDEXs in the HEAD.
  * Added ParseCaption and test and error message for misplaced CAPTION tags
    (if present must be first child of TABLE)
  * Changed "html" in DTD to "HTML" to match examples provided by W3C.
  * Added omitted final "/" in many URLs.
  * Corrected typos in two DTDs.
  * Corrected typos in many comments, and added a few.
  * Changed a few big if-else-if-else-ifs to switch-case-defaults (error
    messages).
  * MoveBeforeTable() would lose the moved nodes if the TABLE was the first
    child of another tag.  Fixed.
  * Added test to IsJavaScript() to first test to make sure node passed is
    indeed a script tag.
  * Wrapped .h files with #ifdefs to prevent double-inclusion
  * Pointed out where some control over whether or not to wrap after = could
    be inserted.
  * Modified slide generation routines to honor user preferences for
    upper-case-tags, upper-case-attrs, and always-quote-attrs, plus attention
    to when XmlOut is true (please check this as I'm not entirely familiar with
    XML syntax).
  * The addition of SmartIndent = yes; to the indent command line argument
    wasn't being reached because of an earlier test for the indent command
    line argument.  Removed second indent test and moved assignment to first.

Affected files:
attrs.c, config.c, html.h, lexer.c, parser.c,
platform.h, pprint.c, tags.c, tidy.c

-- 
          ,=<#)-=#  <http://www.war-of-the-worlds.org/>
     ,_--//--_,
  _-~_-(####)-_~-_  "Did you see that Parkins boy's body in the tunnels?" "Just
(#>_--'~--~`--_<#)  the photos.  Worst thing I've ever seen; kid had no face."