Jeremy Corbell is encouraged and optimistic about the first batch of alien and UFO files being released by the government ... he says the transparency here is a long time coming. The UFO expert and filmmaker joined us Friday on "TMZ Live," and we asked him about the Pentagon releasing photos , videos and files on aliens and unidentified aerial phenomena. Jeremy tells us the White House has told him more files will be released as part of a "slow burn" ... and he hopes that means they are easing