Normalize and sort hotfixes across eggs and versions sections

[stevepiercy]

• Add PloneHotfix20200121
• Fixes #141

Sorry for the ugly diff, but I found that it is easier to audit things when both eggs and versions sections are:

• Sorted in increasing version order
• Use the same comparator syntax and version numbers in tests

I found a couple of places where things were added to one section, but not another.