Implement save/restore cursor position

This passes the vttest for save and restore cursor position. The
implementation was done according to:

    http://www.vt100.net/docs/vt510-rm/DECSC.html

As of yet, there are a few things not supported by the terminal which
should otherwise be saved/restored.

vte was updated for a fix with CSI param parsing

1 files changed, 12 insertions, 0 deletions

diff --git a/src/ansi.rs b/src/ansi.rs
index c9f7e268..b1a70130 100644
--- a/src/ansi.rs
+++ b/src/ansi.rs
@@ -462,6 +462,12 @@ pub enum CharsetIndex {
     G3,
 }
 
+impl Default for CharsetIndex {
+    fn default() -> Self {
+        CharsetIndex::G0
+    }
+}
+
 /// Standard or common character sets which can be designated as G0-G3
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum StandardCharset {
@@ -469,6 +475,12 @@ pub enum StandardCharset {
     SpecialCharacterAndLineDrawing,
 }
 
+impl Default for StandardCharset {
+    fn default() -> Self {
+        StandardCharset::Ascii
+    }
+}
+
 impl<'a, H, W> vte::Perform for Performer<'a, H, W>
     where H: Handler + TermInfo + 'a,
           W: io::Write + 'a