Add options for each runner.

Some runners like PosixRunner, ProcessRunner, PopenRunner supported specific options for their spawn method.
It solves a specific problem such as setup chdir for executing command.

For example command line
```Ruby
cd some_path && zip -X0r file.epub mimetype META-INF OEBPS
```
can be runned as
```Ruby
line = Cocaine::CommandLine.new("zip", "-X0r file.epub mimetype META-INF OEBPS", runner_options: {chdir: "some_path"})
line.run
```