Usage of local.bitstream.redirectToURL

[milanmajchrak]

PR: #647

It is used for uploading big file using a path in v7.
Check original issue: ufal#1094

[milanmajchrak]

Refactoring of uploading the big file is needed:
1. Input field for big file won't be defined in the submission-forms.xml
2. The big file upload step will be added into Upload step
- add a two input fields (file path, file description) there
- add a button Add file there
3. After clicking on the Add file button the file will be upload

Note:
- bigfile Item's metadata won't be deleted after upload
- this input field will be allow only for admin
- this approach allows the admin to upload more big files
- redirectToURL metadata is bitstream's level metadata, not item's

[milanmajchrak]

• The Item's redirectToUrl metadata is removed after every upload
• The cfg property which determines whether the file is removed after upload, was set to false, meaning "do not delete that file."