Uploaded files should not be declared as Bytes

[Brad Crittenden]

In interfaces like IProductRelaseFile and IBugAttachment the attributes that are files to be uploaded are Bytes but get converted to ILibraryFileAlias-es.

We have one test in productreleasefinder that calls Bytes._validate() on the ProductReleaseFile fields and fails because Bytes._validate expects a string not a LibraryFileAlias.

We need to have a new field that accepts bytes returns a ILibraryFileAlias.

When solving this bug it might be good to visit bug 115215.