Use DialTimeout

Figured 5 sec was a good value.  If it takes longer than 5 sec to connect to NATs you've got bigger problems.

I decided against seeding the random ConnectionCluster.  I like the predictability that a non seeded connection pool provides.

I tried to write a test and had a heck of a time with it.  You can see what go itself did to test timeout here: http://golang.org/src/pkg/net/dial_test.go

Let me know if you want a test and I can perhaps look into perhaps some kind of mock or something?