v5.5.0alpha
Build: Only define HAVE_PROGRAM_INVOCATION_NAME if it is set to 1.
Bump version and soname for 5.5.0alpha.
Build: Prepare to support Automake's subdir-objects.
xzdiff: Add support for .lz files.
xz: Includes <time.h> and <sys/time.h> conditionally in mytime.c.
Build: Add support for translated man pages using po4a.