simplify MB new if using newer Alien::Libarchive
bring tests inline with Archive::Ar
documentation and stubs from Archive::Ar
add set_opt and get_opt methods
implement rename
handle IO::Handle
get_data and get_handle implementation
extract method
type detection
keep the errors around, in XS as well as in Perl land
fix pod error
more fixes for error methods
add contains_file method
tiny refactor
implment extract_file
implement clear method
rm stub
implementation for chmod
fix all tests
travis fix