Contract subshells in pretty-printing of spin-configurations

[jagot]

Spin-orbitals belonging to the same sub-shell that are adjacent in a spin-configuration should be contracted when pretty-printing, see

AtomicLevels.jl/test/configurations.jl

Lines 360 to 397 in eca19eb

	@test_broken string.(spin_configurations(c"2s2 2p"s)) ==
	["2s² 2p₋₁α",
	"2s² 2p₋₁β",
	"2s² 2p₀α",
	"2s² 2p₀β",
	"2s² 2p₁α",
	"2s² 2p₁β"]
	@test_broken string.(spin_configurations(c"[Kr] 5s2 5p5 ks"s)) ==
	["[Kr]ᶜ 5s² 5p₋₁² 5p₀² 5p₁α ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀² 5p₁β ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀α 5p₁² ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀β 5p₁² ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀² 5p₁² ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀² 5p₁² ks₀α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀² 5p₁α ks₀β",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀² 5p₁β ks₀β",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀α 5p₁² ks₀β",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀β 5p₁² ks₀β",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀² 5p₁² ks₀β",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀² 5p₁² ks₀β"]
	@test_broken string.(spin_configurations(c"[Kr] 5s2 5p4"s)) ==
	["[Kr]ᶜ 5s² 5p₋₁² 5p₀²",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀α 5p₁α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀α 5p₁β",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀β 5p₁α",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₀β 5p₁β",
	"[Kr]ᶜ 5s² 5p₋₁² 5p₁²",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀² 5p₁α",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀² 5p₁β",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀α 5p₁²",
	"[Kr]ᶜ 5s² 5p₋₁α 5p₀β 5p₁²",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀² 5p₁α",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀² 5p₁β",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀α 5p₁²",
	"[Kr]ᶜ 5s² 5p₋₁β 5p₀β 5p₁²",
	"[Kr]ᶜ 5s² 5p₀² 5p₁²"]

Possibly related to #23.