add _load_params debug overrides for module args/file passed on cmdline

Updated python module wrapper explode method to drop 'args' file next to module.
Both execute() and excommunicate() debug methods now pass the module args via file to enable debuggers that are picky about stdin.
Updated unit tests to use a context manager for masking/restoring default streams and argv.

test/units/mock/procenv.py

@@ -0,0 +1,57 @@
+# (c) 2016, Matt Davis <mdavis@ansible.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import sys
+
+from contextlib import contextmanager
+from io import BytesIO, StringIO
+from ansible.compat.six import PY3
+from ansible.utils.unicode import to_bytes
+
+@contextmanager
+def swap_stdin_and_argv(stdin_data='', argv_data=tuple()):
+    """
+    context manager that temporarily masks the test runner's values for stdin and argv
+    """
+    real_stdin = sys.stdin
+
+    if PY3:
+        sys.stdin = StringIO(stdin_data)
+        sys.stdin.buffer = BytesIO(to_bytes(stdin_data))
+    else:
+        sys.stdin = BytesIO(to_bytes(stdin_data))
+
+    real_argv = sys.argv
+    sys.argv = argv_data
+    yield
+    sys.stdin = real_stdin
+    sys.argv = real_argv
+
+@contextmanager
+def swap_stdout():
+    """
+    context manager that temporarily replaces stdout for tests that need to verify output
+    """
+    old_stdout = sys.stdout
+    fake_stream = BytesIO()
+    sys.stdout = fake_stream
+    yield fake_stream
+    sys.stdout = old_stdout