add ID to upload form and check if ID exist to avoid loading invalid javascript code for read-only views.

check if element really exists before calling it. (e.g. for public shared files view, elements like "navigation" doesn't exist)

Implement support for replacing files during upload with the actions: replace, suggest name, and cancel

- when creating a new text file or directory which name already exist use the same pattern as for file uploads in such a case (add a (N) to the name)
- don't allow renaming if a file/directory with the name already exists