HD44780 serial driver

Hello,

I made a patch for the HD44780 serial driver, because LoS-Panel's keypad 
function did not work properly.
A `diff` against the original hd44780-serial.c from lcdproc 0.5.4:

314a315
 >    unsigned char i,retval;
317c318
<        if (buffer == SERIAL_IF.keypad_escape) {
---
 >        if (buffer == (SERIAL_IF.keypad_escape & 0xFF)) {
321c322,328
<                       return buffer;
---
 >                       for ( i=3 ; i>=0 ; i-- ) {
 >                           if (( buffer % ( 1<<i )) == 0 ) {
 >                               retval = ((i<<4)+(buffer>>4))+0x11;
 >                                   break;
 >                                   }
 >                           }
 >                           return retval;

That's the only file to be altered.

The changes are working for me and Erik Brower (LoS-Panel's creator).

Greetz,
Matthias