SVG : clean arrows

Conflicts:
	images/svg/north_arrows/NorthArrow1.svg
	images/svg/north_arrows/NorthArrow10.svg
	images/svg/north_arrows/NorthArrow11.svg
	images/svg/north_arrows/NorthArrow12.svg
	images/svg/north_arrows/NorthArrow13.svg
	images/svg/north_arrows/NorthArrow14.svg
	images/svg/north_arrows/NorthArrow15.svg
	images/svg/north_arrows/NorthArrow16.svg
	images/svg/north_arrows/NorthArrow2.svg
	images/svg/north_arrows/NorthArrow4.svg
	images/svg/north_arrows/NorthArrow5.svg
	images/svg/north_arrows/NorthArrow6.svg
	images/svg/north_arrows/NorthArrow_blackgreenblack.svg
	images/svg/north_arrows/NorthArrow_blackwhiteblack.svg
	images/svg/north_arrows/NorthArrow_blackyellowblack.svg
	images/svg/north_arrows/NorthArrow_bluegreenblue.svg
	images/svg/north_arrows/NorthArrow_source.svg
	images/svg/north_arrows/default.svg
	images/svg/north_arrows/north-arrow_0_qgis_decoration.svg
	images/svg/north_arrows/north-arrow_10_with_map_layers.svg
	images/svg/north_arrows/north-arrow_11_simple_corner.svg
	images/svg/north_arrows/north-arrow_12_triangular_arrows_with_worldmap.svg
	images/svg/north_arrows/north-arrow_13_checkerboard_earth.svg
	images/svg/north_arrows/north-arrow_14_steering_wheel.svg
	images/svg/north_arrows/north-arrow_15_checkerboard_corner_arrows.svg
	images/svg/north_arrows/north-arrow_16_corner_arrows_unfilled_with_circle.svg
	images/svg/north_arrows/north-arrow_17_corner_n_e.svg
	images/svg/north_arrows/north-arrow_1_simple_half_arrow.svg
	images/svg/north_arrows/north-arrow_2_simple_half_arrow.svg
	images/svg/north_arrows/north-arrow_3_simple_symmetric_triangular.svg
	images/svg/north_arrows/north-arrow_4_double_arrow.svg
	images/svg/north_arrows/north-arrow_5_arrow_in_circle_small_n.svg
	images/svg/north_arrows/north-arrow_6_unfilled_big_arrow_symmetric.svg
	images/svg/north_arrows/north-arrow_7_big_circle_with_small_arrow_unfilled_n.svg
	images/svg/north_arrows/north-arrow_8_checkered.svg
	images/svg/north_arrows/north-arrow_9_half_arrow_unfilled.svg