HN Parse Playlist: Parse and regenerate playlists in several format

This class can parse and regenerate music playlist files in several formats.

The playlists can be read and written either to files or for text strings.

Currently it supports parsing and regeneratings playlists in the formats:

- extended m3u
- pls version 2
- simple m3u

NOTE:
If source is 'simple m3u', you only can save to simple m3u.
If source is 'extended m3u' or 'pls', you can save to any type.

The class can sort a playlist according to a given priority sorting sequence of the fields: type, path, title and time.