added view url for dmsf files

the url http://<appl_addr>/dmsf/files/<file_id>/view allows the user to get a file as http request with content-disposition set to inline
which enables the browser to view files of which it can display the mime-types without downloading them (e.g. insert a image from dmsf into wiki entry)

Conflicts:
	config/routes.rb
Merge pull request #279 from RamDav/devel-1.4.9

added view url for dmsf files