From AppConfig to normalize filesystem paths.
PHP returns paths without a trailing slash.

Added:
- Method `AppConfig::resolveValue()` to replace "%app.*%" with a value on the `AppConfig`.
- Tags to resolve "base_path", "public_path", "cache_path", and "logs_path".

Changed:
- Default connection paths in `FilesystemConfig` to use "%app.base_path%" and "%app.public_path%".
- Default path in `LoggerConfig` to use "%app.logs_path%".
- Routine to resolve any config parameters in the filesystem `LocalAdapter` path.
- Routine to resolve any config parameters in the logger `StreamHandler` path.