Bump version number

This is a patch level release that mainly contains a fix for pkg2sqfs.
It also contains some cleanups and a binary compatibility breaking
change to the package file format.

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

configure.ac

@@ -1,5 +1,5 @@
 AC_PREREQ([2.60])
-AC_INIT([pkgtool], [0.4], [goliath@infraroot.at], pkgtool)
+AC_INIT([pkgtool], [0.4.1], [goliath@infraroot.at], pkgtool)
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([foreign dist-xz subdir-objects])
 AM_SILENT_RULES([yes])