bug fixes for 4.0.3 release

header fix

native engine fixes and small bug fixes

4.0.0 fixes. Native WS API support

refactor to modular design

Merge pull request daltoniam#704 from dessmith/bugfix/plist-version-n…

…umber-correction

Fix version number

Merge pull request daltoniam#636 from daltoniam/swift_5

Swift 5 support

Merge pull request daltoniam#572 from daltoniam/self_swift_4.2

Using s = self in Swift 4.2 way

bug fixes and swift 4.1 support

New error handling. Timeout fix. Small assorted bug fixes