Add a wrapper script to keep ./solcjs available until we can drop it in a breaking release

Author: cameel

solcjs

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -e
+
+script_dir="$(cd "$(dirname "$0")" && pwd)"
+
+[ -e "$script_dir/dist/solc.js" ] || npm run build
+exec "$script_dir/dist/solc.js" "$@" < /dev/stdin