Disable trimwhitespace and drawwhitespace via their configs (#1446)

Instead of completely disabling them, we now use their internal toggle.

Also moved `drawwhitespace` commands inside the plugin.

---

* Fixed bug where commands would show even when plugin was disbled. Also removed antiquated way of disabling.

* Fixed typos.

* Also moved trimwhitespace out of config, if it already has a default enabled value of false.

* Changed documentation.

* Clarified comments.

data/core/command.lua

@@ -107,7 +107,7 @@ end
 function command.add_defaults()
   local reg = {
     "core", "root", "command", "doc", "findreplace",
-    "files", "drawwhitespace", "dialog", "log", "statusbar"
+    "files", "dialog", "log", "statusbar"
   }
   for _, name in ipairs(reg) do
     require("core.commands." .. name)

data/core/commands/drawwhitespace.lua

@@ -1,16 +0,0 @@
-local command = require "core.command"
-local config = require "core.config"
-
-command.add(nil, {
-  ["draw-whitespace:toggle"]  = function()
-    config.draw_whitespace = not config.draw_whitespace
-  end,
-
-  ["draw-whitespace:disable"] = function()
-    config.draw_whitespace = false
-  end,
-
-  ["draw-whitespace:enable"]  = function()
-    config.draw_whitespace = true
-  end,
-})

data/core/config.lua

@@ -101,8 +101,5 @@ setmetatable(config.plugins, {
   end
 })
 
--- Disable these plugins by default.
-config.plugins.trimwhitespace = false
-config.plugins.drawwhitespace = false
 
 return config

data/core/init.lua

@@ -531,12 +531,9 @@ local style = require "core.style"
 
 ------------------------------ Plugins ----------------------------------------
 
--- enable or disable plugin loading setting config entries:
+-- disable plugin loading setting config entries:
 
--- enable plugins.trimwhitespace, otherwise it is disabled by default:
--- config.plugins.trimwhitespace = true
---
--- disable detectindent, otherwise it is enabled by default
+-- disable plugin detectindent, otherwise it is enabled by default:
 -- config.plugins.detectindent = false
 
 ---------------------------- Miscellaneous -------------------------------------