refactor for modularity

[jpeak5]

There are a ton of opportunities to clean up this code:

1. determine file type in a smarter way in smart_autodiscover_filetype() n lib.php
2. collapse repeated regex functions is_matchtype() into a matcher class
3. in classes.php, reduce copy paste code by defining validate_line() and extract_data() in parent classes, overriding where necessary

see the branch refactor