Delete the quote preceding the lambda in spacemacs|add-toggle to avoid
the following warning:
.emacs.d/core/core-toggle.el: (lambda (x) ...) quoted with ' rather than with #'
While #' would be more correct than ', there is no need to quote the
lambda at all.
Modify macro spacemacs|add-toggle to create additional sets of functions for
each supported modes when the toggle is major mode specific.
A toggle is major mode specific when it is bound to keys using the keyword
:evil-leader-for-mode
Updare documentation to add a section on toggles in the Spacemacs concepts.
This commit introduces two new options to add-toggle:
:prefix, a symbol that is bound to the raw prefix argument (as
in `(interactive "P") forms).
:on-message, an expression overriding the default 'on' toggle
message (useful to document a toggle's argument).
These new options are applied to long-lines' toggle, so we can choose
how many lines to toggle it on via a raw prefix argument.
