Add zipdownload for WinOS and OS without system()

Fixed Download on Windows and make downloads possible for Servers
without system() access
Added check for zip extension

add the check for the zip-extension.
Fixed HTML Syntax Error
decide on delete if files should be keeped or syslinks followed
security checks to prevent unwanted changes
fixed minor issues
hide plus icon from projectbar if user has noaccess
Fix issue with search opening duplicate copy of file on result
update check
Change "Cancel" to "Close" to avoid confusion
logout user on download
removed autoupdate code
removed confirmation from dialog
removed permission check
removed user logout
restore version only on first login
save version to data only
Remove extra line break, being picky again :-)