add DEFAULT_DUMP_DIR and HTML_DUMP_DIR constants, for easier cmdline dumps,

add DEFAULT_DUMP_DIR and HTML_DUMP_DIR constants, for easier cmdline dumps,
fixed dumping buttons locally (images/buttons/),
support pages arg for dumphtml,
optional directory arg for dumpserial + dumphtml,
fix a AllPages warning,
show dump warnings/errors on DEBUG,
don't warn just ignore on wikilens pagelist columns, if not loaded.
RateIt pagelist column is called "rating", not "ratingwidget" (Dan?)

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@3753 96ab9672-09ca-45d6-a79d-3d69d39ca109