Parsuricata

Fixed
- Allow option names with periods (e.g. `tls.cert_subject;`). Thanks, [jgrunzweig](https://github.com/jgrunzweig). [GH#10](https://github.com/theY4Kman/parsuricata/issues/10)
- Properly stringify port groupings. Thanks, [jgrunzweig](https://github.com/jgrunzweig). [GH#8](https://github.com/theY4Kman/parsuricata/issues/8)
- Allow ungrouped port ranges (e.g. `alert ip any 80:` or `alert ip any :100`). Thanks, [jgrunzweig](https://github.com/jgrunzweig). [GH#9](https://github.com/theY4Kman/parsuricata/issues/9)

Fixed
- Allow escape sequences in strings. [GH3](https://github.com/theY4Kman/parsuricata/issues/3)

Fixed
- Allow escaped newline before a rule's first option. [GH4](https://github.com/theY4Kman/parsuricata/issues/4)
- Allow trailing newlines before EOF

Added
- Added support for negated settings (e.g. `content: !"stuff";`). [GH5](https://github.com/theY4Kman/parsuricata/issues/5), [GH#1](https://github.com/theY4Kman/parsuricata/issues/1)

Added
- _DOC:_ add usage example to README

Added
- Basic Suricata rules parser
- Basic rules beautification