[test] Use '.' as the field separator in the names

We frequently use '-' within the test name or format name and so we
encounter confusion as '-' is also used as the field separator. At times
this has caused a new test to break an old test because the new test would
match one of the old test's target specific reference images. So switch
everything over to use '.' between fields (test name, target, format,
subtest, etc.).

1 files changed, 0 insertions, 0 deletions

diff --git a/test/gradient-alpha.rgb24.ref.png b/test/gradient-alpha.rgb24.ref.png
new file mode 100644
index 00000000..93ce8f59
--- /dev/null
+++ b/test/gradient-alpha.rgb24.ref.png