Swift 4.2 & Minor API Improvements

Two updates

• Migration of the project to Swift 4.2
• Updated the the method signatures of the parse methods to no longer require escaping closures for the event handler.

Minor fixes and comments

This is a minor release with bug fixes and filling out the documentation comments.

Migrated to Swift 4

The pre-release contains the following:

• Migration of the project to Swift 4
• Introduction of SwiftLint into the project and resolved the code to met the formatting rules.
• Refactored a number of methods to simplify the internal logic.

Improved API & SPM support

The pre-release contains the following:

• Initial support for using HTMLSAXParser as a package from Swift Package Manager.
• Change the API to drop LocationClosure from the HTMLSAXParser.Event enum.
• Change the API to add HTMLSAXParseContext add a new parameter to the EventHandler closure, which can be used to retrieve the parsing location as well as abort the parsing process.
• Additional character encodings supported.

Initial Pre-release

This initial release represents the first release able to process HTML content. There are numerous improvements still to make.