“Everything I Have Is Yours,” Eleanor Henderson (Flatiron Books)A love story and medical mystery all in one, Eleanor Henderson’s memoir “Everything I Have Is Yours” chronicles her husband’s battle with an unidentifiable illness, as well as the toll it takes on their relationship and family.Henderson takes readers through almost a decade of Aaron’s constantly evolving symptoms, from unexplainable lesions on his body to depression to hearing voices to Aaron’s absolute certainty that his body has