Gas Optimizations

[code423n4]

See the markdown file with the details of this report here.

[c4-judge]

Picodes marked the issue as grade-a

[0xhiroshi]

(we are dropping fees altogether, but will answer the above as if we are still implementing it)

G-1: invalid, fee bp and recipient will either be nonzero together, or zero together

G-2: acknowledged

G-3: valid

[c4-sponsor]

0xhiroshi requested judge review