BibDocFile: display file upload progress

• File managemenent interface displays progress of the upload, in browsers that supports XMLHttpRequest Level 2. For others, the progress bar is replaced with a rotating indicator. When the file management interface is not used in asynchrounous upload mode (eg. in WebSubmit function 'Create_Upload_Files_Interface'), simply display the rotating indicator. An additional rotating indicator is displayed after the upload progress reports 100% complete, in order to account for server side post-processing. (closes #1021) (addresses #1020)

• Better handles pressing of 'esc' key, in order not to close the file revision panel (the transfer is interrupted anyway by the browser; Now leaves a chance to make adjustements and "resume").

• Also updates style of "restriction box" for corresponding tooltip to stay on same line.

Tested-by: Tibor Simko <tibor.simko@cern.ch>