Added the binary module for writing binary files to the filesystem.

The binary module accepts a base64 string and a destination parameter. With these it writes bytes out to the file system. While these bytes could technically be ASCII or Unicode (or other text-based encoding), the purpose of this module is to write out binary files to the file system. This allows a base64 string to be checked into version control or, as will be more likely, into group vars.

In my case the base64 string was included in the group vars in Ansible Tower and allowed me to write out separate binary files for separate groups. I submitted this request to the dev mailing list and did not hear any other way to accomplish what I needed. I figured I would submit a pull request and let somebody decide whether it was common enough of a task that a module should be included with Ansible.
When possible, modules should be compatible with python2.4.  hashlib is more recent than that.  So using something like this is more appropriate:
```
try:
    from haslib import sha1
except ImportError:
    from sha import sha as sha1
```

Also note -- if we're just checksumming to confirm the file is the same we should use sha1.  That's because sha1 is available when hashlib is not and md5 (the other hash in python-2.4's stdlib) is not available on systems running in FIPS-140-2 compliance mode.