Initial creation of osxcollector.output_filters module
Fix typo in README
Add domains filter
Fix issue where ChromeHistoryFilter dropped important keys
Remove unnecessary version from osxcollector.output_filters package
Add OpenDNSFilter

The OpenDNSFilter will add a 'osxcollector_opendns' to lines that have a suspicious domain in the 'osxcollector_domains' key.
Running the OpenDNS filter requires having already run the DomainsFilter.

This also introduces a concept of a config file for filters. Each filter can have its own config in a YAML section with the
same name as a the class. This allows for stuff like API keys, whitelists, etc.
Use unbuffered input from stdin when running filters
Find the API for filters to access config

get_config() in osxcollector.osxcollector.OutputFilter takes a key and looks into the proper config.
If the config is missing, it throws a mildly informative message.
Create a base class for creating filters that add threat feed data.
Add a filter for running hashes through VirusTotal
Add details for new filters in README and example YAML
Blacklist and FirefoxHistory output filters

The BlacklistFilter allows checks the value of a key against blacklisted values.
 - Multiple blacklists can be specified in the config file
 - Multiple keys can be matched against a single blacklist
 - Keys to match can be of the form 'a.b' to match "b" in {"a": {"b":"foo"}}
 - Matching can use python regex or straight string compare
 - The values to match are stored in flat files that use # to indicate a line of comments

 The FirefoxHistory filter basically does what ChromeHistoryFilter does but for firefox.
Install precommit hooks and do lots of guided cleanup

Running filters now works in a nice virtualenv.
If you don't know how to use virtualenv, read up:
  http://codefellows.github.io/sea-f2-python-sept14/supplements/virtualenv.html
Enabled autopep8 commit hook
Code review feedback
Merge branch 'output_filters'
Merge README.md