new testsuite r0.5

[Zack Weinberg]

Another update, and diffs from the previous version, are in the usual
place.  Highlights:

- Incorporated fixes to the math and wordexp tests from libc proper.
- Reduced size of two huge files by 90%.  (This is why the diff is so
large.)  
- runtest now handles errors reported during an 'expect' test
correctly.  
- No gcc warnings with the warning level turned way up (see
changelog for exact settings).

zw