CMFM: Support for Intent.ACTION_SEND_MULTIPLE

This changes allows to send multiple files through selecting
multiple files. Add new "Send selection" global menu, that is shown
when user has some selected files, and all of them are files (send multiple
is not allowed for folders)

Change-Id: I1a889c1188803a6639433d4613fec2246d90fc9b
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>