Added id diff filter script

contrib/filter-uuid-patch

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+# Remove all hunks from a patch that don't add the id attribute to minimize the impact (removed
+# comments etc.) of sigma-uuid script.
+#
+# Usually used as follows:
+# 1. Add UUIDs to rules:
+# tools/sigma-uuid -er rules
+# 2. Generate and filter patch
+# git diff | contrib/filter-uuid-patch > rule-uuid.diff
+# 3. Reset to previous state
+# git reset --hard
+# 4. Apply filtered patch
+# patch -p1 < rule-uuid.diff
+#
+# This tool requires an installed unidiff package.
+
+from unidiff import PatchSet
+from sys import argv, stdin
+
+try:
+    with open(argv[1], "r") as f:
+        patch = PatchSet(f.readlines())
+except IndexError:
+    patch = PatchSet(stdin.readlines())
+
+for patched_file in patch:
+    for h in reversed(range(len(patched_file))):
+        hunk = patched_file[h]
+        if not any([ line.is_added and line.value.startswith("id: ") for line in hunk ]):
+            del patched_file[h]
+
+print(str(patch))