Rename formats to attributes

Embeds are also being described with formats which makes less sense,
name should be more general
Remove support for negative lengths for delete

Option potentially just adds confusion
Add docs for delta methods
implement embed interface
add remove attribute tests
fix fuzzer given new embed format
Add fuzzer to more grunt tasks

Add fuzzer to grunt test
Add grunt test:unit
Add grunt coverage:fuzzer
rename methods
add note about compactness