Updated action functions and fixed a few bugs.

(1) Added support for yank shortcuts (up, down, left, right, and line)
in Normal mode.
(2) Updated Keyboard module to fix bug in EncodeKey() function where
keystrokes from the given user key string were being erroneously
duplicated in the generated key sequence.
(3) Updated DeleteLines() action function to fix positioning errors in
various edit control contexts.