[FIX] Filename of downloaded binary from list view
[FIX] Pass options containing context to read_ids()
[FIX] o2m dataset's get_context to take additional context as does _super()
Fix binary fields in one2many widgets:

- Don't retrieve the binary contents just to display the size, but pass context with bin_size=True instead
- Always pass filename in download link

Combination of patches from the bug report from Enrico Ganzaroli, Cedric Le Brouster and the last commit from myself which actually prevents the preloading of the binaries.