Usability Improvements for the Files Application

2 improvements for the file application home page :

• Add a "Upload a new file" button at the top of the application homepage + infobox
• Use the realtime filtering table used for the Index / AllDocs page in XE to display available files

1 improvement for a single file page :

• Add a box warning the user that if the file he uploads to replace a previous one has a different name, it will be renamed to the first file name.

Plus a bonus one that would be needed for XE as well :

• Add support for uploading multiple files at once (à la GMail for now, multiple file location input fields)