libuv-1.0: readdir->scandir, add scandir_next

also add mkdtemp, FS_MKDTEMP, FS_ACCESS, DIRENT types
numeric cmp in bytecode #76
numeric cmp in jit: prepare, so far int only #76
numcmp jit: added new faster ASMS macro, SSE2 insn

not yet finished
numcmp jit: pass xmm asm to X86_CMP, fix ASMS len
travis: add osx (beta)