libgpaste-applet: fix

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
settings-ui: don't call exit

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
gnome-shell: select search on popup

and hide search bar when history is empty

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
gnome-shell: match search case-insensitively

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>