Allow waiting for read and write simultaneously

Do not eagerly wait for IO-readiness
Add Windows and IPv6 DNSResolver support

Also added random picking of DNS Servers, or is it recommended only to switch Namservers when one fails?
Merge pull request #104 from Asmod4n/patch-1

Add Windows and IPv6 DNSResolver support
Add Celluloid::IO::TCPSocket#getsockname
Bump Travis Ruby version to 2.1.1
Update .rspec
Obtain resolv hosts via Resolv::Hosts::DefaultFileName
Revert "Obtain resolv hosts via Resolv::Hosts::DefaultFileName"

This reverts commit aa4a7c3ef3bffc739788fee13324fd3645fb0804.

Ungh, resolv.conf vs hosts
Let Resolv::DNS::Config.default_config_hash do its thing
Use rbx-2
Merge pull request #23 from celluloid/simultaneous-read-write

Celluloid::IO breaks if tasks contend on both reads and writes simultaneously