App update

Submodule web/app 3e86d42..00f3933:
  > Merge branch 'develop' into dek
  > Merge branch 'develop' into dek
  > Merge branch 'develop' into dek
  > Use the DEK key to encrypt and decrypt image data
  > Add the dek encryption and decryption related functions
  > Merge branch 'develop' into dek
  > Move the do_encrypt() and do_decrypt() function to the function.py file
  > Merge branch 'develop' into dek
  > Add the "dek_check" value to the dek table while creating a new submission
  > Add the "dek_check" column in the dek table
  > Merge branch 'develop' into dek
  > Split the AES generic encryption/decryption functino from the user session AES functions
  > Add the donor_dek key to the table upon submission creation
  > Add the "donor_dek" table
  > Add the possibility to return only the PBKDF2 hash instead of the full string