Merge pull request NebulousLabs#2408 from starius/fees

fix docs about sums of Valid and Missed outputs

types/filecontracts.go

@@ -23,10 +23,10 @@ type (
 	// 'WindowStart' and 'WindowEnd'. Upon submitting the proof, the outputs
 	// for 'ValidProofOutputs' are created. If the party does not submit a
 	// storage proof by 'WindowEnd', then the outputs for 'MissedProofOutputs'
-	// are created instead. The sum of 'MissedProofOutputs' must equal
-	// 'Payout', and the sum of 'ValidProofOutputs' must equal 'Payout' plus
-	// the siafund fee.  This fee is sent to the siafund pool, which is a set
-	// of siacoins only spendable by siafund owners.
+	// are created instead. The sum of 'MissedProofOutputs' and the sum of
+	// 'ValidProofOutputs' must equal 'Payout' minus the siafund fee. This fee
+	// is sent to the siafund pool, which is a set of siacoins only spendable
+	// by siafund owners.
 	//
 	// Under normal circumstances, the payout will be funded by both the host and
 	// the renter, which gives the host incentive not to lose the file. The