Implement moveto and copyto commands for choosing a destination name on copy/move

Fixes #227
Fixes #476

cmd/copyto/copyto.go

@@ -0,0 +1,53 @@
+package copyto
+
+import (
+	"github.com/ncw/rclone/cmd"
+	"github.com/ncw/rclone/fs"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	cmd.Root.AddCommand(commandDefintion)
+}
+
+var commandDefintion = &cobra.Command{
+	Use:   "copyto source:path dest:path",
+	Short: `Copy files from source to dest, skipping already copied`,
+	Long: `
+If source:path is a file or directory then it copies it to a file or
+directory named dest:path.
+
+This can be used to upload single files to other than their current
+name.  If the source is a directory then it acts exactly like the copy
+command.
+
+So
+
+    rclone copyto src dst
+
+where src and dst are rclone paths, either remote:path or
+/path/to/local or C:\windows\path\if\on\windows.
+
+This will:
+
+    if src is file
+        copy it to dst, overwriting an existing file if it exists
+    if src is directory
+        copy it to dst, overwriting existing files if they exist
+        see copy command for full details
+
+This doesn't transfer unchanged files, testing by size and
+modification time or MD5SUM.  It doesn't delete files from the
+destination.
+`,
+	Run: func(command *cobra.Command, args []string) {
+		cmd.CheckArgs(2, 2, command, args)
+		fsrc, srcFileName, fdst, dstFileName := cmd.NewFsSrcDstFiles(args)
+		cmd.Run(true, command, func() error {
+			if srcFileName == "" {
+				return fs.CopyDir(fdst, fsrc)
+			}
+			return fs.CopyFile(fdst, fsrc, dstFileName, srcFileName)
+		})
+	},
+}