Add cherry pick of Date::Calculations to Time::Calculations

[calebhearth]

Meet dependencies by requiring active_support/core_ext/date/calculations' in Time::Calculations. Line 101 "d = to_date.advance(options)" uses Date#advance which is defined there.

[arunagw]

Is there any failing test so we can check with that??

[calebhearth]

No I can not, because apparently it works fine.

I am not sure why it was not working for me, nor am I sure why it does work since Date#advance is not defined in Time::Calculations and none of the requires at the top of Time::Calculations add it.

rails[master]/ › irb
>> require 'active_support/duration'
=> true
>> require 'active_support/core_ext/time/zones'
=> true
>> require 'active_support/core_ext/time/conversions'
=> true
>> Date.new.advance minutes: 1
NoMethodError: undefined method `advance' for #<Date: -4712-01-01 (-1/2,0,2299161)>
    from (irb):4
    from /home/caleb/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'
>> Time.new.to_date.advance minutes: 1
NoMethodError: undefined method `advance' for #<Date: 2012-01-26 (4911905/2,0,2299161)>
        from (irb):5
        from /home/caleb/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'

But...

rails[master]/ › irb
>> require 'active_support/core_ext/time/calculations'
=> true
>> Date.new.advance minutes: 1
=> #<Date: -4712-01-01 (-1/2,0,2299161)>

So it clearly works somehow. I'm just not sure where active_support/core_ext/date/calculations is being required, or more specifically where Date#advance is being defined.