Lookaside cache upload is not based on an extension
Files recognized as binaries are uploaded to the lookaside cache. Its
size or file extension doesn't matter. This functionality involves
"import" command. "new-sources" command still allows any file to be
uploaded manually.
JIRA: COMPOSE-4155
Fixes: #484
Signed-off-by: Ondrej Nosek <onosek@redhat.com>