Merge pull request #10 from wking/no-algorithm-new

algorithm: More new removal

algorithm.go

@@ -39,7 +39,7 @@ var (
 )
 
 // Available returns true if the digest type is available for use. If this
-// returns false, New and Hash will return nil.
+// returns false, Digester and Hash will return nil.
 func (a Algorithm) Available() bool {
 	h, ok := algorithms[a]
 	if !ok {
@@ -81,7 +81,7 @@ func (a *Algorithm) Set(value string) error {
 
 // Digester returns a new digester for the specified algorithm. If the algorithm
 // does not have a digester implementation, nil will be returned. This can be
-// checked by calling Available before calling New.
+// checked by calling Available before calling Digester.
 func (a Algorithm) Digester() Digester {
 	return &digester{
 		alg:  a,