remove redundant toLower for topwords
allow for local yacy.stopwords and yacy.badwords list (in DATA/SETTINGS/)
if file in DATA/SETTINGS it is loaded otherwise file in ./defaults is loaded
   (if locale ./defaults/stopwords.xx doesn't exist take solr/lang/stopwords_xx.txt as default)

move yacy.stopwords, yacy.stopwords.de and yacy.badwords.example out of root directory to ./defaults directory
optimize usage of size() cache
reduce number of calls to queue.size() because that may be a bottleneck
during crawling
more stacks shall be considered for on-demand loading, not only
deep-depth stacks to prevent "too many open files" problem