Support <backtab>

* eat.el (eat-term-input-event): Handle '<tab>' and '<backtab>'
events.
* eat.el (eat-term-make-keymap): Bind '<tab>' and '<backtab>'.
* eat.ti (eat-mono): Add 'kcbt' capability.

eat.el

@@ -4366,6 +4366,10 @@ client process may get confused."
            (send "\e\C-?"))
           ('C-M-backspace
            (send "\e\C-h"))
+          ('tab
+           (send "\t"))
+          ('backtab
+           (send "\e[Z"))
           ;; Function keys.
           ((and (pred symbolp)
                 fn-key
@@ -4651,9 +4655,9 @@ EXCEPTIONS is a list of key sequences to not bind.  Don't use
          for i from ?\C-@ to ?\C-?
          do (unless (= i meta-prefix-char)
               (bind (vector i))))
-        ;; Bind `backspace', `delete', `deletechar', and all modified
-        ;; variants.
-        (dolist (key '( backspace C-backspace
+        ;; Bind `tab', `backspace', `delete', `deletechar', and all
+        ;; modified variants.
+        (dolist (key '( tab backtab backspace C-backspace
                         M-backspace C-M-backspace
                         insert C-insert M-insert S-insert C-M-insert
                         C-S-insert M-S-insert C-M-S-insert

eat.ti

@@ -95,6 +95,7 @@ eat-mono|Emacs Eat without colors,
   rmam=\e[?7l,
   smxx=\e[9m,
   rmxx=\e[29m,
+  kcbt=\E[Z,
   kbs=^?,
   kcuu1=\eOA,
   kri=\e[1;2A,