Addproper handling of default kwargs and added special cache_label kwarg handling
Solves #5 (closed).
Also, a cache_label
or _cache_label
kwarg to a function is now a special kwarg. If given, the cached filename will be prepended by this:
@cache
def func(_cache_label = None):
...
func() # produces a filename along .cache/func-<checksum>.pkl
func(_cache_label="second") # produces a filename along .cache/second-func-<checksum>.pkl