The Great Rewrite (fixes #36, #61, #94, #101)

Rewrite of the file model and pulling mechanism. Needs lots of cleanup
and bugfixes, now...

protocol/nativemodel_unix.go

@@ -0,0 +1,25 @@
+// +build !windows,!darwin
+
+package protocol
+
+// Normal Unixes uses NFC and slashes, which is the wire format.
+
+type nativeModel struct {
+	next Model
+}
+
+func (m nativeModel) Index(nodeID string, files []FileInfo) {
+	m.next.Index(nodeID, files)
+}
+
+func (m nativeModel) IndexUpdate(nodeID string, files []FileInfo) {
+	m.next.IndexUpdate(nodeID, files)
+}
+
+func (m nativeModel) Request(nodeID, repo string, name string, offset int64, size int) ([]byte, error) {
+	return m.next.Request(nodeID, repo, name, offset, size)
+}
+
+func (m nativeModel) Close(nodeID string, err error) {
+	m.next.Close(nodeID, err)
+}