bpo-34605: Avoid master/slave terms (GH-9101)

* Replace "master process" with "parent process"
* Replace "master option mappings" with "main option mappings"
* Replace "master pattern object" with "main pattern object"
* ssl: replace "master" with "server"
* And some other similar changes
diff --git a/Tools/README b/Tools/README
index 3552881..6c5fb20 100644
--- a/Tools/README
+++ b/Tools/README
@@ -1,7 +1,7 @@
 This directory contains a number of Python programs that are useful
 while building or extending Python.
 
-buildbot        Batchfiles for running on Windows buildslaves.
+buildbot        Batchfiles for running on Windows buildbot workers.
 
 ccbench         A Python threads-based concurrency benchmark. (*)