Fixed typo from results to result in _execute_raw method

md5sum on bsd

Tested with OS X local connection and Linux remote. The paths to the
md5sum and md5 commands are hardcoded to the most common location. This
will definitely fail if the commands are elsewhere, or if the md5
command doesn't support the -q 'quiet' option.

Better error messaging in utils

When a command responds with json that is unparseable, dump that unpareseable response instead of swallowing it.

Issue471 - import hashlib to sidestep deprecation warnings

Import hashlib if it is there, otherwise import md5.  Adds method
file_digest that wraps the logic on which module to invoke.

Conflicts:
	lib/ansible/runner/__init__.py

Add support for older version of python-apt

Most constants can be overriden with environment variables. 

Evaluate only_if early

Allow a variable in with_items

Assemble module

This adds a module that concatenates (ie. assembles) a file from
fragments in a directory in alphabetical order.  It chains the file
module afterward to fix up ownership and permission.  This also adds
tests for the assemble module with fragments in assemble.d.

Most constants can be overriden with environment variables. Reserved doing anything with the connection options for further review.

Search multiple paths for modules.

Minimal change to allow a list of paths (separated by the typical path
separator) to be searched in sequence for the named module.

Expand vars_files identically for lists and non-lists

Make 'fetch' test for local directories before creating.  Fixes issue #450

Introduce ansible_python_interpreter variable.

Allow variables in notify list

Expand $item for copy and fetch

This allows configuration of the correct python interpreter on the managed system.

The function call has been renamed to better reflect what it does, and we
reduced the number of calls from two to one in case the remote user is not
root.

This patch also fixes a string concatenation in _copy_module() that
should use os.path.join() instead.

This closes #436

More helpful message when ssh fails.