Upload files

Story description:

1.6 As a submitter I want to upload a manuscript
1.7 As a submitter I want to upload supplemental files

Acceptance criteria:

• The submitter should be asked to upload at least one manuscript file and any supporting files.
  • All files require a "Type" to be selected (manuscript, figure, table, or supplemental file)
  • Any supporting files require a label
• In accordance with story 1.5 ("As a sumbitter I want to understand where I am in the process"), the user interface should use the "Steps" UI component to show progress through all submission steps.

Subtasks:

• Extend file storage data model
• Develop interface for uploading, viewing, categorizing, and labeling submission files
• Keep copies of all files uploaded in history