This mr improves implicit dependencies processing by reducing tree leaves by using the following algorithm:
* remove paths which belong to any base package
* remove packages which are (opt)dependencies of one of the package which provides same path. It also tries to handle circular dependencies by excluding them from being "satisfied"
* remove packages which are already satisfied by any children path
* implement local reporter mode
* simplify watcher class
* review changes
* do not update unknown status
* allow empty key patches via api
* fix some pylint warnings in tests
