add holidays for France

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
adapt to Whit Monday changes in fr.ics

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
update holiday names for france

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
add holidays specific to French subdivisions

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
add the rest of France's 3166-2 subdivisions

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>