d/control bump to Standards-Version 3.9.8

d/control bump to Standards-Version 3.9.8

This is the checklist for that bump and we pass them all:

2.1. Version 3.9.8.0
--------------------
     Released February, 2016.
     9.6
          The menu system is deprecated in favor of the Free Desktop menu
          standard.
2.2. Version 3.9.7.0
--------------------
     Released February, 2016.
     10.5
          Symbolic links must not traverse above the root directory.
     9.2.2
          32bit UIDs in the range 65536-4294967293 are reserved for
          dynamically allocated user accounts.
     5.1
          Empty field values in control files are only permitted in the
          `debian/control' file of a source package.
     4.9
          `debian/rules': required targets must not attempt network access.
     12.3
          recommend to ship additional documentation for package `pkg' in a
          separate package `pkg-doc' and install it into `/usr/share/doc/pkg'.

Change-Id: I7cd59b62f548ef6ad1c7c72feddc608c8715ee74
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>