Fix some issues in the emacs/lispref manuals

Fix some issues in the emacs/lispref manuals

* doc/emacs/basic.texi (Continuation Lines):
* doc/emacs/building.texi (GDB User Interface Layout):
* doc/emacs/dired.texi (Misc Dired Features):
* doc/emacs/maintaining.texi (Identifier Search):
* doc/emacs/mark.texi (Using Region):
* doc/emacs/misc.texi (Document View, DocView Conversion):
* doc/emacs/modes.texi (Major Modes):
* doc/emacs/mule.texi (Input Methods, Unibyte Mode):
* doc/emacs/sending.texi (Mail Methods): Replace @code by
@kbd.
* doc/emacs/frames.texi (Text-Only Mouse):
* doc/lispref/maps.texi (Standard Keymaps): Replace @kbd by
@key.
* doc/lispref/compile.texi (Compiler Errors): Write
non-@code{nil} instead of non-nil.
* doc/lispref/debugging.texi (Internals of Debugger):
'backtrace' is not a command.  'debugger-stack-frame-as-list'
is an option.
* doc/lispref/display.texi (Size of Displayed Text):
'window-lines-pixel-dimensions' has a last argument 'left'.
* doc/lispref/display.texi (Attribute Functions):
'set-face-underline' and 'set-face-inverse-video' are
commands.
(Tooltips): 'tooltip-frame-parameters' is an option.
(Bidirectional Display): 'bidi-paragraph-direction' is an
option.
* doc/lispref/frames.texi (Cursor Parameters): 'cursor-type'
is an option.
(Input Focus): Argument FRAME of 'x-focus-frame' is not
optional.
(Child Frames): Both arguments of 'frame-ancestor-p' are
non-optional.  'iconify-child-frame' is an option.
* doc/lispref/os.texi (Killing Emacs):
'kill-emacs-query-functions' is an option.
* doc/lispref/windows.texi (Mouse Window Auto-selection):
'mouse-autoselect-window' is an option.