cc1541.c: some clarifications

- update top comment and fix goof
- update "usage" text
cc1541.c: another source formatting fix
bmp2c64.c: fix for win32

division of negative int gave strange results, so negate AFTER division
bmp2c64: use binary stdout on win32

this preserves unix-style EOL
allow building all on win32, with MinGW installed

- provide a simple getopt implementation for cc1541.c, taken from the net
  and slightly modified to work for this purpose
- avoid 'echo' in Makefile, as not to create windows line endings
- use variables in Makefile to make up for different shell syntax of
  bourne shell and win32 command line
bmp2c64.c: add option for output segment
cc1541.c: unix line-endings and whitespace fixes
cc1541.c: start at track#17 when writing files

staying as close as possible to the directory speeds up loading of the
first files on disk
[broken] testing with loader code
Merge branch 'master' into multipart