Improve gnome integration

The menu definition is correctly installed in /home/ogrisel/.config/menus/applications-merged/Nuxeo\ CAP\ 5.4.2-SNAPSHOT.menu but the content does not always specify nuxeo related entries:

<Menu>
<Name>Applications</Name>
<Menu>
<Directory>Nuxeo-CAP-5.4.2-SNAPSHOT-izpack.directory</Directory>
<Name>Nuxeo CAP 5.4.2-SNAPSHOT</Name>
<Include>
<Filename>Nuxeo Control Panel-1305193103482.desktop</Filename>
<Filename>Start Nuxeo-1305193103482.desktop</Filename>
<Filename>Stop Nuxeo-1305193103483.desktop</Filename>
<Filename>Uninstall-1305193103483.desktop</Filename>
</Include>
</Menu>

Furthermore the icon file referenced in the meny entry is missing:
cat /home/ogrisel/.local/share/applications/Start\ Nuxeo-1305193103482.desktop
[Desktop Entry]
Categories=
Comment=Start Nuxeo
Comment[en]=Start Nuxeo
Encoding=UTF-8
Exec=/home/ogrisel/Nuxeo/nuxeo-cap-5.4.2-SNAPSHOT-tomcat/bin/nuxeoctl gui start
GenericName=
GenericName[en]=
Icon=images/icon-start.ico
MimeType=
Name=Start Nuxeo
Name[en]=Start Nuxeo
Path=/home/ogrisel/Nuxeo/nuxeo-cap-5.4.2-SNAPSHOT-tomcat
ServiceTypes=
SwallowExec=
SwallowTitle=
Terminal=
TerminalOptions=
Type=Application
URL=
X-KDE-SubstituteUID=false
X-KDE-Username=root

Finally the uninstaller should be preceded by "java -jar":

in Uninstall-1305193103483.desktop:
[...]
Exec=/home/ogrisel/Nuxeo/nuxeo-cap-5.4.2-SNAPSHOT-tomcat/bin/uninstaller.jar
[...]