add mask_expected_results.sh

Provide a script to mask timestamps and source file lines in expected results
files: when updating expected changes, it is useful to see the exact semantic
changes, not the timestamp and source file line changes in the git diff.

Change-Id: I785e126b1f5afddd1b722bc5e922ed90970efa8a

mask_expected_results.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+# to prevent diffs due to timing and source file lines, mask some numbers
+
+for target in */expected-results.xml; do
+  sed -i "s/time='[^']*'/time='MASKED'/g" "$target"
+  sed -i 's/ttcn:[0-9]\+/ttcn:MASKED/g' "$target"
+done