Bug fixes and compiler warnings. Unix readline support, pass 1

Fix various compiler warnings.

Fix bug causing double free when a file isn't found.

Fix bug using uninitialized variable parsing null filename.

Fix bug causing crash when format 3 retrieval pointer encountered.

Add support for readline (command line editing and history on Unix)

Untangle NT I/O so it builds without the direct access SCSI API & works.

Report errors as text messages everywhere.

Add MSVC project files.

Implement most of dir/full

Partially implement XABITM

Add help to command tables.

Allow choice of VMS qualifiers or Unix options.
  mount /write // /dev/cdrom
or
  mount -write /dev/cdrom

Parse quoted strings as command parameters.
   Mount /write "/dev/cdrom"
   search [*...]*.txt "My words for you"

Resolve command, parameter & qualifier ambiguity from tables.

Consolidate the various makefiles into a common file with very small
platform-specific wrappers.  This simplifies maintenance.

Add diskio module to allow easy access to .iso images and simulator files.
Removes requirement for loop device or equivalent.  Builds as a separate
executable.

Writes to the ODS2 volumes are broken.

extracters/ods2/phyio.h

@@ -1,4 +1,7 @@
-/* Phyio.h  v1.2-2   Definition of Physical I/O routines */
+#ifndef PHYIO_H
+#define PHYIO_H
+
+    /* Phyio.h  v1.2-2   Definition of Physical I/O routines */
 
 /*
         This is part of ODS2 written by Paul Nankervis,
@@ -30,11 +33,13 @@
 
 */
 
+#include <stdio.h>
+
 #define PHYIO_READONLY 1
 
 struct phyio_info {
     unsigned status;
-    unsigned sectors;
+    unsigned long long sectors;
     unsigned sectorsize;
 };
 
@@ -42,3 +47,6 @@ void phyio_show(void);
 unsigned phyio_init(int devlen,char *devnam,unsigned *handle,struct phyio_info *info);
 unsigned phyio_read(unsigned handle,unsigned block,unsigned length,char *buffer);
 unsigned phyio_write(unsigned handle,unsigned block,unsigned length,char *buffer);
+void phyio_help(FILE *fp );
+
+#endif