get zone from RubyTime (fixes #3303)

[tdaitx]

According to the spec spec/ruby/core/time/strftime_spec.rb "%Z" and RubyTime#zone should behave the same:

  it "returns the timezone with %Z" do
    time = Time.local(2009, 9, 18, 12, 0, 0)
    zone = time.zone
    time.strftime("%Z").should == zone
  end

This fixes #3303 by calling RubyTime#zone directly.

[headius]

Perhaps we could just abstract the 0:00 to UTC logic into a separate method both call? Like getRubyTimeZoneName or something? The fix you have here ends up creating intermediate (and wasteful) Time and String objects on the way to a Java string, just to reuse that timezone-naming logic.

[tdaitx]

Closing as a new proposal has been submitted (#3331).