rename Ssh class to SshInstance

ts/smartssh.classes.sshdir.ts

@@ -4,9 +4,15 @@ import * as helpers from "./smartssh.classes.helpers";
 import {SshKey} from "./smartssh.classes.sshkey";
 import {SshConfig} from "./smartssh.classes.sshconfig";
 export class SshDir { // sshDir class -> NOT EXPORTED, ONLY FOR INTERNAL USE
-    path:string;
+    path:string; // the path of the ssh directory
     constructor(sshDirPathArg:string){
-        this.path = sshDirPathArg;
+        let sshDirPath:string;
+        if(sshDirPathArg){
+            sshDirPath = sshDirPathArg;
+        } else {
+            sshDirPath = plugins.smartpath.home
+        }
+        this.path = sshDirPath;
     }
     sync(sshConfigArg:SshConfig,sshKeysArg:SshKey[]){