bug fixed
docstring changed
left module contents for later consideration
remove classmethod, methods only callable by instance
add adjquote data fetcher
add some common daily data fetchers
docstrings changed
add fetchers for barra data
add fetcher for index components data
index quote fetcher
add fetcher for interval data
docstrings changed
industry data fetcher
removed redundant docstrings
make this class init stricter
docstrings changed
some constants
useful in generating alphas for test
factory method for filters
negate,intersect,union filters