* Make some SwiftLintFramework declarations public
If built-in rules depend on them.
This will allow separating the rules from the core infrastructure in
separate modules in an upcoming PR.
It also helps formalize the API contract for what should be accessible
to rule implementations.
* Exclude extensions from jazzy
We were using this lock to guarantee a new ID for every file, but we can
get that benefit by using values that are guaranteed to be unique
without the need for locks, such as a UUID.
For example, if `CGFloat` is used in a file where only `UIKit` is imported but not `CoreGraphics`, this will be a violation even if the file previously compiled.
This is because Swift allows referencing some declarations that are only transitively imported.
Enabling the `require_explicit_imports` configuration option will require that the module of every declaration referenced in a source file be explicitly imported.
This will add significant noise to the imports list, but has a few advantages:
1. It will be easier to understand all the dependencies explicitly referenced in a source file.
2. Correcting the `unused_import` rule will no longer introduce compilation errors in files that compiled prior to the correction.
If missing imports are added to a file when correcting it, the `sorted_imports` rule will be automatically run on that file.
If you with to allow some imports to be implicitly importable transitively, you may specify the `allowed_transitive_imports` configuration:
```yaml
unused_import:
require_explicit_imports: true
allowed_transitive_imports:
- module: Foundation
allowed_transitive_imports:
- CoreFoundation
- Darwin
- ObjectiveC
```
JP Simard