Fix segment util to not smoosh segments when a 0% temp is overriding multiple scheduleds

@jebeck 

This is a PR for the changes to make segments work like you said you wanted them.  It, however, doesn't currently pass all tests (it passes all my tests as I expect it to).

It doesn't pass basalutil's test and I tried to look at what was going on, but gave up on trying to figure out what is actually being tested or what the code is doing.  Hopefully you will understand why it's failing faster than me and be able to fix it.

I also skipped another bad test from segmentutil's tests.  It's making the assumption that things will be squished, but it's not incorporating enough fields.  There's a comment in there about why it's wrong.  We can either have check all of the fields that are being used to verify equality in segment util or eliminate it as a test.