document ankidev and remove sync changes

https://github.com/ankitects/anki/pull/548

README.development

@@ -107,3 +107,12 @@ User-contributed instructions for building using Cygwin:
 1. Open a `cmd.exe` (command prompt) on the Anki repository and run the command `sh run`
     1. Do not use `bash run` because it my call for Windows Subsystem for Linux
     1. Do not use any Cygwin terminal as `mintty.exe` because the `rust lang` compiler does not work with them
+
+Enviromental Variables
+-----------------------
+
+If ANKIDEV is set before starting Anki, some extra log messages will be printed on stdout,
+and automatic backups will be disabled - so please don't use this except on a test profile.
+
+If LOGTERM is set before starting Anki, warnings and error messages that are normally placed
+in the collection2.log file will also be printed on stdout.

pylib/anki/sync.py

@@ -13,7 +13,7 @@ from typing import Any, Dict, List, Optional, Sequence, Tuple, Union
 import anki
 from anki.consts import *
 from anki.db import DB
-from anki.utils import checksum, devMode, ids2str, intTime, platDesc, versionWithBuild
+from anki.utils import checksum, ids2str, intTime, platDesc, versionWithBuild
 
 from . import hooks
 from .httpclient import HttpClient
@@ -470,9 +470,6 @@ class HttpSyncer:
         self.prefix = "sync/"
 
     def syncURL(self) -> str:
-        if devMode:
-            url = "https://l1sync.ankiweb.net/"
-        else:
         url = SYNC_BASE % (self.hostNum or "")
         return url + self.prefix