Add script for online-cache building

gradle/reprod/prepareCache.sh

@@ -0,0 +1,21 @@
+# Collects build artifacts that aren't present in the online cache
+# into a subfolder that can be merged with the online cache
+# This script isn't expected to function on OSX.
+
+set -e
+set -x
+
+# Step one: copy all artifacts into subfolder under new name
+rm -rf artifactCache
+mkdir artifactCache
+cd artifactCache
+for f in $(find ../deps/repo -type f); do
+    cp $f $(sha256sum $f | cut -d' ' -f1)
+done
+
+# Step two: remove all files that are already in the cache
+for f in *; do
+    if wget -q --spider "https://www.johni0702.de/replaymod/artifact/$f"; then
+        rm $f
+    fi
+done