Support of multi server deploying

This changes allow works with many server at once:
1. Allows to call several `connect()`
2. Allows to group servers and make changes on servers from particular group

It is especially important when many identical servers work with general database server and we want at first update application files on all app servers and then run database migration on the single server.

We use this fork in some SaaS project for deploying and other bulk actions :)

Parameter `$argv` introduced for working with input arguments and options.