There’s a great subject and story at the heart of “Rebel Hearts,” a documentary about a group of feminist nuns who banded together to become a serious thorn in the side of the patriarchal Catholic Church. These women are unsung heroes of religious history when it comes to their role in breaking down barriers, and their contributions to women’s rights are to be applauded. During the 1960s, the progressive nuns at the Immaculate Heart in Hollywood ran a women’s college that fostered independent thought and social activism. Some of the sisters marched with Martin Luther King Jr., and others cr...