CMDscan.l fix for block comments

The CMDscan.l file which is used to generate the TorqueScript scanner has a bug with how it handles block comments. Currently the handler looks like this:

"/*" {
      register int c;
      for ( ; ; )
      {
         while ( (c = CMDgetc()) != '*' && c != EOF )
         ; /* eat up text of comment */

         if ( c == '*' )
         {
            while ( (c = CMDgetc()) == '*' )
            ;
            if ( c == '/' )
               break; /* found the end */
         }

         if ( c == EOF )
         {
            CMDerror( "EOF in comment" );
            break;
         }
      }
   }

The first and biggest issue is that this fails to increment the line count. This causes the line numbers for TorqueScript opcodes to be incorrect which in turn makes the TelnetDebugger return incorrect line numbers when stepping thru script and fail to accept valid breakpoints. I think this has cause a few of the Torsion bug reports i've gotten with regards to breakpoints not working.

Second the use of CMDgetc() here is incorrect. CMDgetc() reads directly from the buffer and skips characters already in scanners cache. yyinput() is the right function which reads from the cache and refills it using CMDgetc() if need be. This is importaint because you often have a /* followed by a newline... if you skip reading from the cache you can miss a newline and all the opcode lines are off again.

Finally if you fix both of those the logic of this handler is wrong. It won't accept Javadoc style /** */ block comments as any * found screws up the loop. And this implementation came right out of the flex documentation... is that cheating? :)

So after spending 2 hours learning Flex and figuring all this out i have a new comment block handler:

"/*" {
         register int c = 0, l;
         for ( ; ; )
         {
            l = c;
            c = yyinput();

            // Is this an open comment?
            if ( c == EOF )
            {
               CMDerror( "unexpected end of file found in comment" );
               break;
            }

            // Increment line numbers.
            else if ( c == '\n' )
               lineIndex++;

            // Did we find the end of the comment?
            else if ( l == '*' && c == '/' )
               break;
         }
      }

This works correctly in all cases.

While i was at it i fixed the CMDerror() function to properly report error messages.

void CMDerror( char* format, ... )
{
   char error[1024];
   va_list args;
   va_start( args, format );
   _vsnprintf( error, sizeof(error), format, args );

   if ( fileName )
      Con::errorf(ConsoleLogEntry::Script, "%s Line: %d - %s", fileName, lineIndex, error );
   else 
      Con::errorf(ConsoleLogEntry::Script, error);

   gSyntaxError = true;
}

I hope this can make it into all the TAPs quickly... especially TGB with the forthcoming flood of contest participants.