Description
Set the resource handle to retrieve the data for the download.
The resource handle supplied will be closed after sending the download.
Set $handle to null if you want to unset.
Note:
This cannot be used with resources of databases that populate their
BLOBs as resource handles like PostgreSQL. A possible solution
would be to write a stream wrapper.
Returns a PEAR_Error if $handle
is no valid resource or not null.
