Refactor key encoding

Cannot have key names in global namespace as not all key names are valid
python identifiers. So move them into a dict.

kittens/tui/line_edit.py

@@ -3,7 +3,14 @@
 # License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
 
 from kitty.fast_data_types import truncate_point_for_length, wcswidth
-from kitty.key_encoding import RELEASE, HOME, END, BACKSPACE, DELETE, LEFT, RIGHT
+from kitty.key_encoding import RELEASE, K
+
+HOME = K['HOME']
+END = K['END']
+BACKSPACE = K['BACKSPACE']
+DELETE = K['DELETE']
+LEFT = K['LEFT']
+RIGHT = K['RIGHT']
 
 
 class LineEdit:

kittens/tui/loop.py

@@ -19,8 +19,8 @@ from kitty.fast_data_types import (
     close_tty, normal_tty, open_tty, parse_input_from_terminal, raw_tty
 )
 from kitty.key_encoding import (
-    ALT, CTRL, PRESS, RELEASE, REPEAT, SHIFT, C, D, backspace_key,
-    decode_key_event, enter_key
+    ALT, CTRL, PRESS, RELEASE, REPEAT, SHIFT, backspace_key,
+    decode_key_event, enter_key, K
 )
 from kitty.utils import screen_size_function, write_all
 
@@ -28,6 +28,9 @@ from .handler import Handler
 from .operations import init_state, reset_state
 
 
+C, D = K['C'], K['D']
+
+
 def debug(*a, **kw):
     from base64 import standard_b64encode
     buf = io.StringIO()