Adjust configure* for new libewf version

xmount fails to compile against libewf 20130416-2,
replaced libewf_open with libewf_handle_open.
Bump Standards-Version to 3.9.4
Add libbfio-dev to Build-Depends

Fixes:

| In file included from xmount.c:56:0:
| /usr/include/libewf.h:35:21: fatal error: libbfio.h: No such file or directory
|  #include <libbfio.h>
|                      ^
| compilation terminated.

when compiling against libewf 20130416-2.
Release new version 0.5.0-3