Make normalize_by_copy_number.py quiet

Set verbose option to default of False instead of True for transferring of metadata.
Merge pull request #59 from mlangill/less_verbosity

Make normalize_by_copy_number.py quiet
added categorize_by_function script
added new downstream analysis tutorial

this addresses issue #47
Merge pull request #61 from gregcaporaso/issue-47

added new downstream analysis tutorial
Merge pull request #60 from wasade/categorize_by_function

added categorize_by_function script