First commit of new module.
Added adetatime.c and updated build .am file to include it.  Successful build.
Added some function bodies in adatetime.c.
Refactored the create and set methods.  Removed comparison mode from the structure - it is only used as a parameter to the comparison functions now.
Added comparison functions.
Fixed the order of the date and time component comparisons.
Added some adatetime unit tests.
Added more unit tests.
Updated and added unit tests.  Added null checks.
Added a datetime range module and test file.
Added date range test to build.
Added some more unit tests for the date time range functions.
Refactored the name 'adatetime' to the more manageable 'atm'.  It uses the tm structure so this makes sense.
Reworked create, copy, and set methods.
Added atm_set_original() to make use of the original time that is retained in the atm structure.
Refactored the copy functions.  They no longer take dst and src paramaters, only src.  The new instance is allocated in the method.  Minor comment additions to add return values.
Changed the existing gm element of the atm structure to an anonymous union with the members gm and utc inside.  This way the programmer can refer to this element by either name.
Updated comments, then added docs for the atm and the atm_range modules.