`emacsclient` started with `-c` or `-t` argument create a new frame that shall
not be used to manage X windows.
Also fix some related input focus issues (with some remaining unfixed).
Close#17.
* Fix `exwm-reset`
* Make input mode buffer local
* Allow window to stay in `char-mode` while setting input focus to other window
or switching to other workspace
* Prevent marking the end of a key sequence with a single `C-u'.
* Enable `C-u' prefix for key simulation since it's not possible for users to
define simulation keys starting with `C-u'.
* Make Emacs idle only after the visual parts are updated to prevent from
disturbing users.
* Should use '?\s' instead of '? '.
