add getter/setter for self.base.conf.cachedir in rpmkit.updateinfo.yumbase
use list comprehension instead of filter(); see also http://docs.quantifiedcode.com/python-code-patterns/readability/using_map_or_filter_where_list_comprehension_is_possible.html
s/data_g/hsdata/ (convert generator to a list)
add a method to set to cacheonly mode