Clofarabine, Melphalan, and Thiotepa Followed By a Donor Stem Cell Transplant in Treating Patients With High-Risk and/or Advanced Hematologic Cancer or Other Disease

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed diagnosis of 1 of the following: * Acute myelogenous leukemia, meeting 1 of the following criteria: * In first complete remission (CR), meeting 1 of the following criteria: * Poor risk \[no t(15,17), inv 16, or t(8,21)\] * Not a candidate for total body irradiation (TBI) * Any infant in first CR * In second CR, meeting the following criteria: * All patients * In more than second CR OR relapsed/refractory disease, meeting the following criteria: * All patients * Blast percentage \> 5% and \< 25% in bone marrow (BM) at the time of stem cell transplantation (SCT) * Acute lymphoblastic leukemia, meeting 1 of the following criteria: * In first CR, meeting 1 of the following criteria: * Poor risk \[t(9;22), t(4;11) AND no CR after 7-28 days of induction\] * Not a candidate for TBI * Any infant in first CR * In second CR, meeting the following criteria: * All patients * In more than second CR OR relapsed/refractory disease, meeting the following criteria: * All patients * Blast percentage \> 5% and \< 25% in BM at the time of SCT * Acute undifferentiated or biphenotypic leukemia, meeting the following criteria: * All patients * Blast percentage \> 5% and \< 25% in BM at the time of SCT * Chronic myelogenous leukemia, meeting the following criteria: * All patients * In first…