Revise for xdis 3.6.0 ...

Simplify xdis imports where we can.
Blacken (most) of those buffers too

__pkginfo__.py

@@ -21,6 +21,17 @@
 # less elegant than having it here with reduced code, albeit there
 # still is some room for improvement.
 
+# Python-version | package | last-version |
+# -----------------------------------------
+# 2.5            | pip     |  1.1         |
+# 2.6            | pip     |  1.5.6       |
+# 2.7            | pip     | 19.2.3       |
+# 2.7            | pip     |  1.2.1       |
+# 3.1            | pip     |  1.5.6       |
+# 3.2            | pip     |  7.1.2       |
+# 3.3            | pip     | 10.0.1       |
+# 3.4            | pip     | 19.1.1       |
+
 # Things that change more often go here.
 copyright   = """
 Copyright (C) 2015-2020 Rocky Bernstein <rb@dustyfeet.com>.
@@ -58,7 +69,7 @@ entry_points       = {
     ]}
 ftp_url            = None
 install_requires   = ["spark-parser >= 1.8.9, < 1.9.0",
-                      "xdis >= 4.5.1, < 4.6.0"]
+                      "xdis >= 4.6.0, < 4.7.0"]
 
 license            = "GPL3"
 mailing_list       = "python-debugger@googlegroups.com"