Added buffer to the console

Added hotkeys to switch between console buffers and to return to the home one
Added clear screen command
Added debug text outputs to the hello command and when loading sh

sysproc.c

@@ -95,6 +95,10 @@ int sys_uptime(void)
 int sys_greeting(void)
 {
     cprintf("Hello again\n");
+    cprintf("Using Console: %d\n", getcurrentconsoleindex());
+    cprintf("Current PID: %d\n", myproc()->pid);
+    cprintf("Current Parent PID: %d\n", myproc()->parent->pid);
+    cprintf("Process Console: %d\n", myproc()->consoleIndex);
     return 0;
 }
 
@@ -119,4 +123,25 @@ int sys_shutdown(void)
         outw(0x604, 0x2000);
     }
     return 0;
+}
+
+int sys_screen(void) 
+{
+    struct proc *curproc = myproc();
+    int result = 0;
+    int consoleindex = -1;
+    if ((consoleindex = newconsole()) != 0)
+    {        
+        curproc->consoleIndex = consoleindex;
+        switchtoconsole(consoleindex);        
+        wakeup(myproc()->chan);        
+        result = 1;
+    }    
+    return result;
+}
+
+int sys_cls(void)
+{
+    clearscreen();
+    return 0;
 }