Rewrote the t6963 driver:

- Limit the maximum size to 40x16 (240x128 pixel) and change the RAM locations
to make use of 8 KB only. (If one's display is larger and has more memory this
may have to be changed.)
- Drive control lines using defines from lpt-port.h without using a function.
- Use timing.h for delays (which are now optional).
- Remove any use of the graphic area and mode settings, except for optionally
clearing of graphic memory on start-up.
- Remove any cursor related stuff.
- Handle displays correctly which width (in pixels) is not a multiple of the
cellwidth (e.g. 128x64).
- Remove double buffering (display updates are already really fast).
- Update text and font memory using AUTO WRITE function.
- Remove the bignum stub. Now at least something is displayed.
- Fix character offset for bar graphs.
- Make local functions static and inline the most commonly used read / write
functions.

ChangeLog

@@ -12,6 +12,7 @@ v.0.5dev (ongoing development)
  * All drivers: Refactor CGmode enum into lcd.h
  * hd44780: New (possible faster) screen update algorithm
  + Add an option to start LCDd with screen rotation disabled (M. Zanetti)
+ * Rewrite of the t6963 driver fixing several problems (see commit note).
 
 v0.5.4
  * Update driver includes and LDFLAGS (fixed glk and bayrad binding error)