Only operate on non-downloaded packages and repos for same

# Please enter the commit message for your changes.
# (Comment lines starting with '#' will not be included)
# On branch master
# Changes to be committed:
#   (use "git reset HEAD^1 <file>..." to unstage)
#
#	modified:   presto.py
#
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	presto.py~