Fix DECALN behavior

fix-decaln-behavior.diff

diff --git a/VT100Screen.m b/VT100Screen.m
index a0d4db5..1e03101 100644
--- a/VT100Screen.m
+++ b/VT100Screen.m
@@ -1997,6 +1997,12 @@ static BOOL XYIsBeforeXY(int px1, int py1, int px2, int py2) {
             }
             aLine[WIDTH].code = EOL_HARD;
         }
+        // reset scroll region
+        SCROLL_TOP = 0;
+        SCROLL_BOTTOM = HEIGHT - 1;
+        // set cursor to (1, 1)
+        [self setCursorX:0 Y:0];
+
         DebugLog(@"putToken DECALN");
         [self setDirty];
         break;