Vemurafenib Recruiting Phase 2 Trials for Sarcoma, Osteogenic / BRAF NP_004324.2:p.V600X / Rhabdoid Tumors / Stage IV Childhood Non-Hodgkin Lymphoma / Recurrent Childhood Central Nervous System Neoplasm / Ependymomas / Recurrent Childhood Non-Hodgkin Lymphoma / Advanced Malignant Solid Neoplasm / Ewing's Sarcoma (ES) / Stage III Childhood Non-Hodgkin Lymphoma / Malignant Gliomas / Soft Tissue Sarcoma (STS) / Hepatoblastomas / Malignant Germ Cell Tumor / Refractory Malignant Solid Neoplasm / Langerhans Cell Histiocytosis (LCH) / Recurrent Neuroblastoma / Histiocytosis / Recurrent Malignant Solid Neoplasm / Wilms' tumor / Peripheral Primitive Neuroectodermal Tumor / refractory Non-Hodgkin's lymphoma / Refractory Central Nervous System Neoplasm / Refractory Neuroblastoma / Rhabdomyosarcomas Treatment