directory as cache area.

add/update test tools for Tie::Journaled{File,Dir} modules.

clean up Tie::JournaledFile
o remove header in the cache file
o $self->{ 'key' }
o $debug is on if $ENV{'debug'} is defined.
o more carefull check of whether the value is defined or not.
o quotemeta() for pre search key in find()
o rename grep() to find()

create cache file if not exists at the first time.
add the comment on format and creatd time in it.

implement store() operations using _store(), _puts() newly defined