Fix CUU and CUD cursor handling

app/assets/javascripts/ansi-interpreter.js.coffee

@@ -6,7 +6,7 @@ class AsciiIo.AnsiInterpreter
   PATTERNS:
     "\x07": (data) -> # bell
     "\x08": (data) -> @terminal.bs()
-    "\x0a": (data) -> @terminal.cursorDown()
+    "\x0a": (data) -> @terminal.cursorDown 1
     "\x0d": (data) -> @terminal.cr()
     "\x0e": (data) ->
     "\x0f": (data) ->

app/assets/javascripts/terminal.js.coffee

@@ -156,13 +156,15 @@ class AsciiIo.Terminal
       @cursorX += 1
       @updateLine()
 
-  cursorUp: ->
+  cursorUp: (n) ->
+    for i in [0...n]
       if @cursorY > 0
         @cursorY -= 1
         @updateLine @cursorY
         @updateLine @cursorY + 1
 
-  cursorDown: ->
+  cursorDown: (n) ->
+    for i in [0...n]
       if @cursorY + 1 < @lines
         @cursorY += 1
         @updateLine @cursorY - 1