Add support for automatically saving modified date on edits.
Add a method to get the current time

This allows all dates, such as modified_date and createdate to use the exact same time, without initing the current time needlessly.
Fix some shameful typos in the documentation.
Only update the modified date on an object if it is modified.
Move getCurrentTime() along side the other get methods.
Merge pull request #26 from isaacgrant/admin-object-edit-modified-date

Add support for automatically saving modified date on edits.