Change metadata handling on upload

[vmbrasseur]

From the code:

# TODO: change this to a boolean to avoid the +=1 each iteration of the loop
#       just set it to FALSE at the end of its if block
num = 1

This is just used to determine whether it's the first file uploaded to the item. If it is, it includes the metadata. If not, no metadata is needed.

You will probably need to have a look at the item to determine some of this.

• Item exists?
  • Don't send metadata (would clobber existing metadata)
• Item doesn't exist?
  • Only send metadata with first file uploaded