activate gedit plugins in Fedora 21 with Gnome 3.14

Fedora 21 has many plugins for GEdit, which must be installed as packages.

$ sudo dnf search gedit
===================================================================== N/S Matched: gedit =====================================================================
gedit.x86_64 : Text editor for the GNOME desktop
gedit-plugins.x86_64 : Plugins for gedit
gedit-plugin-git.x86_64 : gedit git plugin
gedit-plugin-charmap.x86_64 : gedit charmap plugin
gedit-plugin-synctex.x86_64 : gedit synctex plugin
gedit-plugin-terminal.x86_64 : gedit terminal plugin
gedit-plugin-textsize.x86_64 : gedit textsize plugin
gedit-plugin-bookmarks.x86_64 : gedit bookmarks plugin
gedit-plugin-commander.x86_64 : gedit commander plugin
gedit-plugin-dashboard.x86_64 : gedit dashboard plugin
gedit-plugin-joinlines.x86_64 : gedit joinlines plugin
gedit-plugin-multiedit.x86_64 : gedit multiedit plugin
gedit-plugin-zeitgeist.x86_64 : gedit zeitgeist plugin
rabbitvcs-gedit.x86_64 : Gedit extension for RabbitVCS
gedit-plugin-drawspaces.x86_64 : gedit drawspaces plugin
gedit-plugin-codecomment.x86_64 : gedit codecomment plugin
gedit-plugin-colorpicker.x86_64 : gedit colorpicker plugin
gedit-plugin-smartspaces.x86_64 : gedit smartspaces plugin
gedit-plugin-colorschemer.x86_64 : gedit colorschemer plugin
gedit-cossa.x86_64 : gedit plugin for GTK+ themes previewing
gedit-plugin-wordcompletion.x86_64 : gedit wordcompletion plugin
gedit-plugin-bracketcompletion.x86_64 : gedit bracketcompletion plugin
gedit-latex.x86_64 : gedit plugin for composing and compiling LaTeX documents
gedit-devel.x86_64 : Support for developing plugins for the gedit text editor
gedit-devel.i686 : Support for developing plugins for the gedit text editor
gedit-beesu-plugin.x86_64 : Allows normal users to open files in gedit as root
gedit-code-assistance-devel.i686 : Development files for gedit-code-assistance
gedit-code-assistance-devel.x86_64 : Development files for gedit-code-assistance
gedit-code-assistance.x86_64 : gedit plugin for code assistance for C, C++ and Objective-C
gedit-code-assistance.i686 : gedit plugin for code assistance for C, C++ and Objective-C
gedit-plugins-data.x86_64 : Common data required by plugins

After starting of GEdit in Gnome 3.14, I didn't find any menu-item to activate the plugins.

The "tricky" part is to get the preference menu from the top bar of the
gnome desktop as seen in the picture below:

Here you get the preferences window, in which you can activate the plugins.