Introduce general.el & rewrite map!

+ Now uses an overriding keymap for leader keys, so that it is always
  available, even outside of normal/visual states. In insert/emacs
  states, or in sessions where evil is absent, an alternative prefix is
  used for leader/localleader keys. See these variables:
  + doom-leader-prefix
  + doom-leader-alt-prefix
  + doom-localleader-prefix
  + doom-localleader-alt-prefix
+ Keybinds now support alternative prefixes through the new :alt-prefix
  property. This is useful for non-evil users and non-normal evil
  states. By default, this is M-SPC (leader) and M-SPC m (localleader).
+ Removed +evil-commands flag from config/default (moved to
  feature/evil/+commands.el).
+ config/default/+bindings.el has been split into
  config/default/+{evil,emacs}-bindings.el, which one is loaded depends
  on whether evil is present or not. The latter is blank, but will soon
  be populated with a keybinding scheme for non-evil users (perhaps
  inspired by #641).
+ The define-key! macro has been replaced; it is now an alias for
  general-def.
+ Added unmap! as an alias for general-unbind.
+ The following modifier key conventions are now enforced for
  consistency, across all OSes:
    alt/option      = meta
    windows/command = super
  It used to be
    alt/option      = alt
    windows/command = meta
  Many of the default keybinds have been updated to reflect this switch,
  but it is likely to affect personal meta/super keybinds!

The map! macro has also been rewritten to use general-define-key. Here
is what has been changed:

+ map! no longer works with characters, e.g. (map! ?x #'do-something) is
  no longer supported. Keys must be kbd-able strings like "C-c x" or
  vectors like [?C-c ?x].
+ The :map and :map* properties are now the same thing. If specified
  keymaps aren't defined when binding keys, it is automatically
  deferred.
+ The way you bind local keybinds has changed:

    ;; Don't do this
    (map! :l "a" #'func-a
          :l "b" #'func-b)
    ;; Do this
    (map! :map 'local "a" #'func-a
                      "b" #'func-b)

+ map! now supports the following new blocks:
  + (:if COND THEN-FORM ELSE-FORM...)
  + (:alt-prefix PREFIX KEYS...) -- this prefix will be used for
    non-normal evil states. Equivalent to :non-normal-prefix in general.
+ The way you declare a which-key label for a prefix key has changed:

    ;; before
    (map! :desc "label" :prefix "a" ...)
    ;; now
    (map! :prefix ("a" . "label") ...)

+ It used to be that map! supported binding a key to a key sequence,
  like so:

    (map! "a" [?x])  ; pressing a is like pressing x

  This functionality was removed *temporarily* while I figure out the
  implementation.

Addresses: #448, #814, #860
Mentioned in: #940

modules/config/default/config.el

@@ -1,11 +1,5 @@
 ;;; config/default/config.el -*- lexical-binding: t; -*-
 
-(if (featurep! +bindings) (load! "+bindings"))
-
-
-;;
-;; Config
-
 ;; Don't store authinfo in plain text!
 (setq auth-sources
       (list (expand-file-name "authinfo.gpg" doom-etc-dir)
@@ -86,47 +80,10 @@
   (advice-add #'newline-and-indent :around #'doom*newline-indent-and-continue-comments))
 
 
-(when (featurep 'evil)
-  (when (featurep! +evil-commands)
-    (load! "+evil-commands"))
+;;
+;; Doom's keybinding scheme
 
-  (when (featurep! +bindings)
-    (defvar +default-repeat-forward-key ";")
-    (defvar +default-repeat-backward-key ",")
-
-    (eval-when-compile
-      (defmacro do-repeat! (command next-func prev-func)
-        "Makes ; and , the universal repeat-keys in evil-mode. These keys can be
-customized by changing `+default-repeat-forward-key' and
-`+default-repeat-backward-key'."
-        (let ((fn-sym (intern (format "+evil*repeat-%s" (doom-unquote command)))))
-          `(progn
-             (defun ,fn-sym (&rest _)
-               (define-key! evil-motion-state-map
-                 +default-repeat-forward-key #',next-func
-                 +default-repeat-backward-key #',prev-func))
-             (advice-add #',command :before #',fn-sym)))))
-
-    ;; n/N
-    (do-repeat! evil-ex-search-next evil-ex-search-next evil-ex-search-previous)
-    (do-repeat! evil-ex-search-previous evil-ex-search-next evil-ex-search-previous)
-    (do-repeat! evil-ex-search-forward evil-ex-search-next evil-ex-search-previous)
-    (do-repeat! evil-ex-search-backward evil-ex-search-next evil-ex-search-previous)
-
-    ;; f/F/t/T/s/S
-    (setq evil-snipe-repeat-keys nil
-          evil-snipe-override-evil-repeat-keys nil) ; causes problems with remapped ;
-    (do-repeat! evil-snipe-f evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-F evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-t evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-T evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-s evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-S evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-x evil-snipe-repeat evil-snipe-repeat-reverse)
-    (do-repeat! evil-snipe-X evil-snipe-repeat evil-snipe-repeat-reverse)
-
-    ;; */#
-    (do-repeat! evil-visualstar/begin-search-forward
-                evil-ex-search-next evil-ex-search-previous)
-    (do-repeat! evil-visualstar/begin-search-backward
-                evil-ex-search-previous evil-ex-search-next)))
+(when (featurep! +bindings)
+  (if (featurep 'evil)
+      (load! "+evil-bindings")
+    (load! "+emacs-bindings")))