clib2 Code

- The internal 'struct fd' file descriptor table entry data structure
now has a user data field entry.

- Rearranged the contents of the 'struct fd' file descriptor table entry
data structure in preparation for making it public. Also added a version
field so that user code can handle changes to it gracefully. The default
file is no longer a BCPL pointer to a file handle by default, but
both a BPTR and a socket identifier, wrapped into a union.

- Added experimental tilde expansion in Unix path names. This still needs
some more work.

- Removed an unnecessary (STRPTR) cast.

- Added some documenting comments to the source code.

- __get_default_file() called __fd_unlock() without having called
__fd_lock() first. Ouch.

- Removed an unnecessary pair of __fd_lock()..__fd_unlock() calls from
ttyname_r().

- Unlink is now reentrant, or at least thread-safe.

- You can now make unlink() stop after a failed deletion attempt which
failed because the object to be deleted was reported as being "in use".
The libunix.a variant defaults to report the deletion to have succeeded
under these circumstances and later tries to delete the files marked
for deletion. See <dos.h> for a brief documentation of how to change
the behaviour.

- Added the base_dir_nametest test program.

- basename() and dirname() can no longer return NULL. They truncate the
resulting path name instead. This is done so because some code that
calls basename() or dirname() does not check if the function's return
value is NULL.

- Forgot to update chown() to use the same bug fix as fchown().

- The SetOwner() fall-back code for Kickstart 2.04 was passing the wrong
parameters to the file system. The first (dp_Arg1) should have been
zero. Ouch.