* LLama.Examples: RepoUtils.cs → ConsoleLogger.cs

* LLama.Examples: Examples/Runner.cs → ExampleRunner.cs

* LLama.Examples: delete unused console logger

* LLama.Examples: improve splash screen appearance

the llama_empty_call() no longer shows configuration information on startup, but it will display it automatically the first time a model is engaged

* LLama.Examples: Runner → ExampleRunner

* LLama.Examples: improve model path prompt

The last used model is stored in a config file and is re-used when a blank path is provided

* LLama.Examples: NativeApi.llama_empty_call() at startup

* LLama.Examples: reduce console noise when saving model path

Conversations can be "forked", to create a copy of a conversation at a given point. This allows e.g. prompting a conversation with a system prefix just once and then forking it again and again for each individual conversation. Conversations can also be "rewound" to an earlier state.

Added two new examples, demonstrating forking and rewinding.