Fixes #354.
Merge pull request #355 from herby/gh-354

Fixes #354.
Inlined HTMLSnippet >> snippetAt:put:

snippetAt:install: is the user-faced api.
Also removed HTMLSnippet >> snippetAt:ifAbsent:
which was only used in dnu handler.
- Fixed issue #356
- Added SetTest >> testComparing
Merge branch 'snippet-cleaning' of https://github.com/herby/amber

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Fixes issue #356
Using set equality in some tests where workarounds were before.
Merge pull request #358 from herby/using-set-equality

Using set equality in some tests where workarounds were before.