Merge master: the modules moved into a package

Every file this branch touches moved into dikte/, so the merge is mostly the
rename following the edits. What needed a hand:

hotkey.py: master replaced the _macos()/_gnome() pair with one backend()
chooser, and this branch had added _windows() to the pair. Windows is a fifth
value of the chooser now, and everything that used to ask "macOS or Windows?"
asks backend() instead. The key is held by the running process there, so
installs_shortcuts() and shortcut_needs_restart() are both false for it, and
desktop_name() says Windows.

install.ps1 and the Windows README name dikte/__main__.py, the entry point the
Linux and macOS installers were pointed at in the same commit. The Start Menu
entry, the autostart entry and the dikte.cmd shim all come off one $entry
variable.

settings_ui.py: the shortcut tab now has a Windows sentence of its own, with
the Turkish for it. Falling through to the branch master wrote for a desktop
with no registry would have told a Windows user to check /dev/input. Nothing
covers that branch: there is no Windows Settings test class, the way there is
one for macOS.

CONTRIBUTING: the chooser it names is backend() now, and the test count is the
merged one, 1067 of 1110 running anywhere.

tests/test_ggml.py

@@ -18,8 +18,8 @@ import time
 import zipfile
 from unittest import mock
 
-import ggml
-import hub
+from dikte import ggml
+from dikte import hub
 from tests.support import (DikteTest, fake_urlopen, http_error, json_body,
                            linux_only, url_error)
 
@@ -449,7 +449,7 @@ class Catalogue(Local):
 
 
 STAND_IN = textwrap.dedent("""
-    import http.server, sys, threading, time
+    import http.server, socketserver, sys, threading, time
 
     args = sys.argv[1:]
 
@@ -475,7 +475,17 @@ STAND_IN = textwrap.dedent("""
         def log_message(self, *a):
             pass
 
-    server = http.server.HTTPServer((opt("--host"), int(opt("--port"))), Handler)
+    # The same server, without the reverse lookup of the address it bound.
+    # http.server asks the resolver for the name behind 127.0.0.1 in between
+    # binding and listening; on a Mac nothing answers and the call sits in a
+    # timeout for half a minute, all of it with the port still closed and a
+    # start waiting on it.
+    class Bound(http.server.HTTPServer):
+        def server_bind(self):
+            socketserver.TCPServer.server_bind(self)
+            self.server_name, self.server_port = self.server_address[:2]
+
+    server = Bound((opt("--host"), int(opt("--port"))), Handler)
     print("listening on " + opt("--port"), flush=True)
     server.serve_forever()
 """)