Mitoxantrone Recruiting Phase 2 Trials for Blasts 10 Percent or More of Bone Marrow Nucleated Cells / Refractory Acute Myeloid Leukemia / acute, recurrent Myeloid Leukemia / Chronic Myelomonocytic Leukemia-2 / High Grade Malignant Neoplasm / Myelodysplastic Syndrome / Recurrent Adult Acute Myeloid Leukemia / Previously Treated Myelodysplastic Syndromes / Myelodysplastic Syndrome With Excess Blasts-2 / Myeloid Neoplasm / Recurrent Childhood Acute Myeloid Leukemia Treatment