Create ftoptions option to disable auto settings

Closes #662

runtime/help/options.md

@@ -167,6 +167,12 @@ Default plugin options:
 
 	default value: `on`
 
+* `ftoptions`: by default, micro will set some options based on the filetype. At the moment, micro will
+   use tabs for makefiles and spaces for python files regardless of your settings. If you would like to
+   disable this behavior turn this option off.
+
+	default value: `on`
+
 Any option you set in the editor will be saved to the file 
 ~/.config/micro/settings.json so, in effect, your configuration file will be 
 created for you. If you'd like to take your configuration with you to another

runtime/plugins/ftoptions/ftoptions.lua

@@ -1,9 +1,17 @@
+if GetOption("ftoptions") == nil then
+    AddOption("ftoptions", true)
+end
+
 function onViewOpen(view)
+    if not GetOption("ftoptions") then
+        return
+    end
+
     local ft = view.Buf.Settings["filetype"]
 
     if ft == "makefile" or ft == "go" then
         SetOption("tabstospaces", "off")
-    elseif ft == "python" then
+    elseif ft == "python" or ft == "python2" or ft == "python3" then
         SetOption("tabstospaces", "on")
     end
 end