debian/control: bump up standards version to 3.9.6
lintian: adding new override
debian/gridvis.desktop: adding some Keywords
d/g-d-w.sh: switching the JRE usage dynamically

If the gridvis.conf gets a 'jdkhome = jre' we want to use the preshipped
JRE from the package, mostly needed to run the GridVis-Desktop probably
with the shipped Java version.
debian/rules: fix package-contains-timestamped-gzip

Lintian complains about files with timestamps. Fixed up by using -n on
the gzip command.
debian/rules: removing dh_shlibdeps for now

The jre/ folder contains prebuilded statically librarys and exceutables,
so there is currently no need for dh_shlibdeps to collect various
dependencies.
debian/rules: adopting changes related to the jre/ folder