Added no-private and no-permutation flags

[ramimac]

Not sure if you're accepting pull requests, but I added a couple minor options that I found useful. Implementation is quick and dirty - happy to change if you have opinions.

Added:

• --no-private flag to bucket_finder and bucket_crawler, suppresses printing of private buckets and objects
• --no-perm flag to bucket_finder, only scans using raw wordlist