Re: More axes for `ftmulti`

[Werner LEMBERG]

>>  ?           display this help screen
> And F1 as commonly used for help [...]

Thanks.  Here is what I've now committed, and I'm quite satisfied now.

```
F1, ?       display this help screen
q, ESC      quit ftmulti
F2          toggle axis grouping
F3          toggle outline hinting
F4          toggle embedded bitmaps
F5          toggle anti-aliasing
F6          cycle through hinting engines (if available)

space       toggle rendering mode

, .         previous/next font

Up, Down    change pointsize by 1 unit
PgUp, PgDn  change pointsize by 10 units

Left, Right adjust index by 1
F7, F8      adjust index by 16
F9, F10     adjust index by 256
F11, F12    adjust index by 4096

a, A        adjust axis 0
b, B        adjust axis 1
...
p, P        adjust axis 16

-, +        adjust axis range increment
```


    Werner