Merge softuart/cpm back into trunk:

Merge softuart/cpm back into trunk:
* cpm/bios.asm:
  - read/write: Get error code from avr part and return it to caller.
  - Added dph/dpb for ramdisk.
  - boot: If ramdisk exists, clear directory area, and copy ccp+bdos from boot disk.
  - wboot: Load system from ramdisk, if feasible.
  - Added print hex  and reorderd functions to ease debugging.
* cpm/ipl.asm
  - Increased number of sectors to load from 49 to 51 (= all reserved sectors).
* cpm/Makefile:
  - oflag=direct removed from installcpm target.

git-svn-id: svn://cu.loc/avr-cpm/trunk@63 57430480-672e-4586-8877-bcf8adbbf3b7