Remember command's optoins

Store options in file in home folder. 
Use just '.tddium' file, because when I save options and then user enter command without them I can't guess from what host use config file (e.x. '.tddium' or '.tddium.localhost').

https://bugs.tddium.com/bugzilla/show_bug.cgi?id=619
A test for params_helper is not sufficient.

There needs to be a test that calls

~~~
 Tddium::TddiumCli.send("server:set", options)
~~~

And checks either that `write_params` was called, or that the setting file was actually written out.