lang/org: major refactor

The motivation for this change was to rethink lang/org's flags. Many of
its former flags represented non-features. Therefore, its flags have
been reduced to five: +dragndrop, +ipython, +pandoc, +gnuplot and
+present. Everything else is included as org-load-hooks and treated as
reasonable defaults.

Other changes:
- Fixes #1502: don't autopair certain pairs when in a math region
- Fixes #1483: broken localleader in org-agenda
- Adds gnuplot support #1108
- Doom's org submodules have been moved into lang/org/contrib/, because
  I expect there will be *many* more to come, and I don't want to
  pollute the moudle's root.

modules/lang/org/contrib/ipython.el

@@ -0,0 +1,38 @@
+;;; lang/org/contrib/babel.el -*- lexical-binding: t; -*-
+
+(def-package! ob-ipython
+  :defer t
+  :init
+  (defvar +ob-ipython-local-runtime-dir nil)
+
+  (setq ob-ipython-resources-dir ".ob-ipython-resrc")
+
+  (defun +org|babel-load-ipython (lang)
+    (and (string-prefix-p "jupyter-" (symbol-name lang))
+         (require 'ob-ipython nil t)))
+  (add-hook '+org-babel-load-functions #'+org|babel-load-ipython)
+  :config
+  (set-popup-rules!
+    '(("\\*ob-ipython.*"
+       :slot 2 :side right :size 100 :height 0.2
+       :select nil :quit nil :transient nil)
+      ("^\\*Python"
+       :slot 0 :side right :size 100
+       :select nil :quit nil :ttl nil)
+      ("\\*Python:.*"
+       :slot 0 :side right :size 100
+       :select nil :quit nil :transient nil)))
+
+  ;; advices for remote kernel and org-src-edit
+  (advice-add 'ob-ipython--create-repl :override #'+org*ob-ipython--create-repl)
+  (advice-add 'org-babel-edit-prep:ipython :override #'+org*org-babel-edit-prep:ipython)
+  (advice-add 'org-babel-execute:ipython :override #'+org*org-babel-execute:ipython)
+  (advice-add 'org-babel-ipython-initiate-session :override #'+org*org-babel-ipython-initiate-session)
+
+  ;; retina resolution image hack
+  (when (eq window-system 'ns)
+    (advice-add 'ob-ipython--write-base64-string :around #'+org*ob-ipython--write-base64-string))
+
+  ;; ipython has its own async keyword, disable ipython in ob-async.
+  (after! ob-async
+    (add-to-list 'ob-async-no-async-languages-alist "ipython")))