Immigration is obviously both a hot button topic and the hot potato of American politics.  It's also the focus of three short documentaries that play at the Crest Theatre on Tuesday evening on the fifth day (of ten) of the 11th Annual Sacramento Film & Music Festival.  Coincidentally, all three films were made by students at either Berkeley or Stanford and they complement each other to form a fascinating program. "Iraq in the US" has a unique Sacramento connection, focusing on the lives of Iraqi refugees who have been relocated here to build new lives.  "New American Soldier" tells the stories of several green card holders who joined the US military to become eligible for citizenship - co