Fix FreeBSD issues for elfpatch.  First line of "ldd" is the binary name...

Fix FreeBSD issues for elfpatch.  First line of "ldd" is the binary name.
Also add default output filename for 'elfpatch' rather than stdout when stdout is a TTY.

Note the line beginning `/bin/ls:` in the example output below.

```
$ uname -a
FreeBSD freebsd11 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r267488: Sun Jun 15 06:48:36 UTC 2014     root@grind.freebsd.org:/usr/obj/usr/src/sys/GENERIC  i386
$ ldd /bin/ls
/bin/ls:
        libutil.so.9 => /lib/libutil.so.9 (0x2806f000)
        libncurses.so.8 => /lib/libncurses.so.8 (0x28081000)
        libc.so.7 => /lib/libc.so.7 (0x280c1000)
```