Add build script that wraps stack

@thorsten ist das skript halbwegs sinnvolles bash?

build.sh

+#!/usr/bin/env bash
+
+# A simple wrapper around stack
+#
+# This exists mainly to make it easier to pass arguments to test and benchmark
+# suites.
+
+if [[ $# -eq 0 ]]; then
+    cat <<EOF
+Usage: $0 COMMAND [OPTS]
+
+Commands:
+---------
+
+b[uild] [OPTS]                  build project
+
+t[est] u[nit] [OPTS]            run unit tests
+t[est] e[xamples] [OPTS]        run exampes
+t[est] d[octests] [OPTS]        run doctests
+t[est] [OPTS]                   run all testsuites
+
+bench [OPTS]                    run the benchmark suite
+
+r[un] [OPTS]                    run the main program
+
+haddock [OPTS]                  build documentation
+EOF
+    exit 1
+fi
+
+doTest() {
+    if [[ $# -eq 0 ]]; then
+        exec stack test
+    fi
+
+    case "$1" in
+        u|unit|s|spec)
+            exec stack test :spec --test-arguments "${*:2}"
+            ;;
+        e|examples)
+            exec stack test :examples --test-arguments "${*:2}"
+            ;;
+        d|doctests)
+            exec stack test :doctests --test-arguments "${*:2}"
+            ;;
+        *)
+            exec stack test "$@"
+    esac
+}
+
+doBench() {
+    exec stack bench :bench --benchmark-arguments "$*"
+}
+
+case "$1" in
+    b|build)
+        exec stack build "${@:2}"
+        ;;
+    t|test)
+        doTest "${@:2}"
+        ;;
+    bench)
+        doBench "${@:2}"
+        ;;
+    r|run)
+        exec stack exec ma -- "${@:2}"
+        ;;
+    haddock)
+        exec stack haddock :ma "${@:2}"
+        ;;
+    *)
+        echo "Unknown command $1"
+        exit 1
+esac