* Add Example wrapper in order to display test failures inline when running in Xcode.
* Stop using Swift 5.1-only features so we can compile on Xcode 10.2.
* Wrap strings in Example.
* Add Changelog entry.
* Wrap all examples in Example struct.
* Better and more complete capturing of line numbers.
* Fix broken test.
* Better test traceability.
* Address or disable linting warnings.
* Add documentation comments.
* Disable linter for a few cases.
* Limit mutability and add copy-and-mutate utility functions.
* Limit scope of mutability.
The MIT license doesn't require that all files be prepended with this
licensing or copyright information. Realm confirmed that they're ok with this
change. This will enable some companies to contribute to SwiftLint and the
date & authorship information will remain accessible via git source control.