Factor out common test functionality to test/common.sh.in.
diff --git a/.gitignore b/.gitignore
index 2b255db..cb53d22 100644
--- a/.gitignore
+++ b/.gitignore
@@ -65,6 +65,7 @@
 test/*.rf64
 test/*.w64
 test/*.wav
+test/common.sh
 test/cuesheet.diff
 test/cuesheet.log
 test/metaflac-test-files/out.meta