Remove dependency on Exificient due to licensing incompatibility

Exificient is licensed under GPLv2 with no intention to add the
classpath exception (witnessed in at
http://sourceforge.net/p/exificient/discussion/856595/thread/6017013e/).
Remove all dependencies on it, pending reimplementation using a more
open library (OpenEXI looks like a good candidate).

Change-Id: I589367be593ebc275c7551d9e6008b74d8461de5
Signed-off-by: Robert Varga <rovarga@cisco.com>