optimized and simplified many thread-related functions.
-eliminated resource leak races in thread cancellation.
+eliminated resource leak races in thread cancellation. (almost all
+existing implementations, including glibc, have these leaks.)
overhauled stdio implementation to take advantage of readv/writev for
reduced syscall load, and improved stdio's handling of error status.
strangthened tmpnam/tempnam/tmpfile filename generation and made the
straight C functions not depend on POSIX symbols.
+
+fixed pthread cancellation ABI on i386 to match the LSB/glibc ABI
+
+better double-free handling in malloc
+
+various minor bug fixes