RICHEDIT: use buffers rather than linked lists for input and out buffers

[Ge van Geldorp]

> From: Mike McCormack
> 
> This patch writes the output of the RTF parser into the edit 
> control in 
> 1024 byte chunks, and reads the input via a char[1024] buffer, rather 
> than a linked list of single characters.

Not that it should matter very much, but the MS control always seems to
read the input in 4096 byte chunks. Maybe you could enlarge InputBuffer
from 0x400 to 0x1000?

Ge van Geldorp.