- Reorganize headers, and update TODO.

- The incoming TS is GMT... but the hole filler wants local time so we
have to convert it.
- Change e-mail address

- Rename tl_config.h to timelib_config.h

- Improve portability.
# TODO: The standalone lib needs it's own build stuff, pretty much same as
# Zend has for standalone builds.

- Rename "datetime.c" and "datetime.h" to "timelib.c" and "timelib.h" to
prevent duplicate header names.