* When the -w option is used during extraction, the path specified
is now first created if it does not already exist.
* The command line tool now exits with a failure return code if an
error occurs during extraction.
* A "catch-all" header file (lhasa.h) has been added.
* The public header files installed with the library can now be
included and used externally.
* A pkgconfig file is now installed as part of the library
(thanks Jan Engelhardt).
* Make targets have been added for building Doxygen documentation
and including them as part of the distribution.
