Issues/50 from ical, cleaned up

Cleanup of #226.

Squashed all commits into one, removed non-ical changes, unbroke tests, and committed. Sorry to have lost all the contributors, but it was too unwieldy to rebase. Credits to @skyporter @jgauby @btucker @spra85.

I hope this helps in getting iCal parsing finally merged.
Hey! I should preface this by saying I'm just a third party whose interested in this project, and I'm not entirely knowledgeable of everything.
Anyway, Here's the behaviour I have observed:
`
[1] pry(main)> DateTime.now.to_s
=> "2014-11-19T10:03:57-08:00"
[2] pry(main)> DateTime.now.class
=> DateTime
[3] pry(main)> DateTime.now.to_time.class
=> DateTime
[4] pry(main)> DateTime.now.utc.to_time.class
=> Time
[5] pry(main)> show-method DateTime.now.to_time

From: /home/thann/.rvm/gems/ruby-2.1.2/gems/activesupport-3.2.19/lib/active_support/core_ext/date_time/conversions.rb @ line 68:
Owner: DateTime
Visibility: public
Number of lines: 3

def to_time
  self.offset == 0 ? ::Time.utc_time(year, month, day, hour, min, sec, sec_fraction * (RUBY_VERSION < '1.9' ? 86400000000 : 1000000)) : self
end
`