build, data: the Greek capitals by name; one way to run python3; bench.sh checks its own binary

Δ Γ Λ Ω Φ Ψ Σ Θ answered only to De, Ga, La, Om, Ph, Ps, Si, Th, while
their small letters answered to delta, gamma and the rest; they answer to
the names too now.  mkemoji and cldr2emoji write UTF-8 whatever the
locale, as the other generators already did; verify-map calls python3 the
one way; the tests' include path drops a directory nothing includes
through; and bench.sh says which binary is missing instead of blaming the
daemon ten seconds later.

tests/Makefile

@@ -3,7 +3,7 @@ LD = 9l
 HOSTCC = cc
 PKG_CONFIG ?= pkg-config
 CFLAGS ?= -O2 -g
-UNIT_CPPFLAGS = -I.. -I../cutest
+UNIT_CPPFLAGS = -I..
 UNIT_CFLAGS = -std=c99 -Wall -Wextra
 HOST_CFLAGS = -std=c99 -Wall -Wextra
 TEXT_CFLAGS = $(shell $(PKG_CONFIG) --cflags pangocairo cairo fontconfig)