Add very basic test

t/basic.t

+#!/bin/sh
+#set -x
+
+NR=0
+
+t() {
+    NR=$(expr $NR + 1)
+    if eval "$1"; then
+        echo "ok $NR - $2"
+    else
+        echo "not okay $NR - $2"
+    fi
+}
+
+if [ "$(basename "$(readlink -f .)")" != "t" ]; then
+    cd t || exit 1;
+fi
+
+echo 1..4
+
+t "echo test > testfile.$$ && ../cachestats -q testfile.$$" "file is cached"
+t "while ../cachestats -q testfile.$$; do ../cachedel testfile.$$ && sleep 1; done" "file is not cached any more"
+t "! ( env LD_PRELOAD=../nocache.so cat testfile.$$ >/dev/null && ../cachestats -q testfile.$$ )" "file is still not in cache"
+t "! ( env LD_PRELOAD=../nocache.so cp testfile.$$ testfile.$$.2 && ../cachestats -q testfile.$$.2 )" "copy of file is not cached"
+
+# clean up
+rm -f testfile.$$ testfile.$$.2