This is second of three big naming convention changes. In this commit,
we change the naming conventions for hook functions and variable
functions:
1. Replace the bar | to indicate a hook function with a -h suffix, e.g.
doom|init-ui -> doom-init-ui-h
doom|run-local-var-hooks -> doom-run-local-var-hooks-h
2. And add a -fn suffix for functions meant to be set on variables,
e.g.
(setq magit-display-buffer-function #'+magit-display-buffer-fn)
See ccf327f8 for the reasoning behind these changes.
This is in preparation for general.el integration coming in 2.1.1. It is
very likely that map! will change (and even more, be split into several
macros). Not much, but change none-the-less. Specifically, the state
keywords (e.g. :nvi, :n, :i) will be removed in favor of a :state
property that takes a list, e.g. (normal visual insert).
In any case, both map! and general are also relatively expensive
compared to define-key and evil-define-key* (and the new define-key!
macro), so use that when we can.
This also means changes to either API won't affect Doom's modules in the
long term.
