Drop/deprecate 'auto' layer detection support

- Remove 'auto' mode from ksconf package.
- Add warning about using 'auto' for combine.  (This has been around longer,
  and there wasn't a warning previously.  Honestly, this one may not be a big
  problem.  Lets issue a warning and see if there's any pushback.)

ksconf/commands/combine.py

@@ -185,7 +185,7 @@ def f(pattern):
             Use ``dir.d`` if you have directories like ``MyApp/default.d/##-layer-name``, or use
             ``disable`` to manage layers explicitly and avoid any accidental layer detection.
             By default, ``auto`` mode will enable transparent switching between 'dir.d' and 'disable'
-            (legacy) behavior.
+            (legacy) behavior, however this option will be removed in a future release.
             """)
 
         parser.add_argument("-q", "--quiet", action="store_true",
@@ -252,9 +252,9 @@ def run(self, args):
         args.source = list(expand_glob_list(args.source, do_sort=True))
 
         if args.layer_method == "auto":
-            self.stderr.write(
-                "Warning:  Automatically guessing an appropriate directory layer detection.  "
-                "Consider using '--layer-method' to avoid this warning.\n")
+            from warnings import warn
+            warn("Using 'auto' layer detection will not be supported in future releases.  "
+                 "Consider using '--layer-method' to avoid this warning", DeprecationWarning)
             if len(args.source) == 1:
                 layer_method = "dir.d"
             else:

ksconf/commands/package.py

@@ -93,11 +93,10 @@ def f(pattern):
             "are specified, then all layers will be included.")
 
         player.add_argument("--layer-method",
-                            choices=["dir.d", "disable", "auto"],
+                            choices=["dir.d", "disable"],
                             default="dir.d",
                             help="Set the layer type used by SOURCE.  "
-                                 "Additional description provided in in the ``combine`` command."
-                                 "Note that 'auto' is no longer supported as of v0.10.")
+                                 "Additional description provided in in the ``combine`` command.")
         player.add_argument("-I", "--include", action="append", default=[], dest="layer_filter",
                             type=wb_type("include"), metavar="PATTERN",
                             help="Name or pattern of layers to include.")
@@ -209,15 +208,6 @@ def run(self, args):
         packager = AppPackager(args.source, app_name, output=self.stderr,
                                template_variables=template_vars)
 
-        if args.layer_method == "auto":
-            # There'd no way to make this option legal but not shown in argparse.  :-(
-            # Yeah, all this needs *LOTS* of work!
-            self.stderr("The 'auto' option for layer_method is not longer supported.  "
-                        "This will be an error in v0.11 and removed in v0.12\n")
-            from ksconf import __version__
-            if __version__.startswith("0.11."):
-                return EXIT_CODE_CLI_ARG_DEPRECATED
-
         with packager:
             packager.combine(args.source, args.layer_filter,
                              layer_method=args.layer_method,