[ji] make java.util.Date duck type some of Ruby's Time

[kares]

that would probably help some user confusion: #2049

currently Time auto-coerces to java.util.Date (e.g. with Java collections) and it stays that way :

require 'active_support/all'
1.second # 1 second
Time.now.beginning_of_day # works

list = java.util.ArrayList.new
list.add(1)
list.add(Time.now)

list.get(0).second # 1 second
list.get(1).beginning_of_day # undefined method `beginning_of_day' for #<Java::JavaUtil::Date:0x409986fe>

[kares]

OK, due how java.util.Date handles months this probably won't be done (to play safe):

• Java's date.getMonth returns 0-11
• date.getMonth is aliased as date.month (0-11)
• Ruby's Time#month returns 1..12 so this would collide ;(

[kares]

won't fix since it would get confusing to return a different month based on Java/Ruby calls.
probably a solution - in the long term - would be moving to Java 8's new date/times APIs ...