* Let the AddHours(), Add*() return itself, so that they can be chained.
* Made the previous *Name() methods static and added non-static versions that
take the day/month of the object.
* Make BDateTime::Date/Time() return references (const or non-const).
* Fixed the BDateTime comparison operators.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35894 a95241bf-73f2-0310-859d-f6bbb57e9c96