/bin: make utilities quit on error

bin/gen_api_header.sh

@@ -1,6 +1,6 @@
 #!/bin/env sh
 # single header api generator with clang
 
-set +e
+set -e
 
 clang -I./ -P -E -nostdinc -nobuiltininc -DTWN_NOT_C $TWNROOT/include/twn_game_api.h 2> /dev/null | clang-format

bin/twn

@@ -1,7 +1,7 @@
 #!/bin/env sh
 # townengine tooling interface
 
-set +e
+set -e
 
 exe="$(basename $PWD)"
 toolpath="$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")"