fixing support for Unix sockets in native binding

Binding natively connections to Unix sockets failed due to DNS lookups applied on pathname to Unix socket's folder.
Merge pull request #249 from booo/unix_sockets

fixing support for Unix sockets in native binding (rebased)
add ConnectionParameters object
remove node-tap
1. behave correctly if copy to/from is send to db by query method (report error in standart way); 2. bugfix and code review in native copy to implementation
bugfix: correctly create new connection for canceling copy to query
handle situation, when broken copy to query, ends before it is canceled
add tests that checks error reporting for incorrect copy to/copy from usage. add tests for fixed bug in native copy from implementation
bugfix. sometimes native copy to loose rows
version bump