SF bug 1524317: configure --without-threads fails to build

Moved the code for _PyThread_CurrentFrames() up, so it's no longer
in a huge "#ifdef WITH_THREAD" block (I didn't realize it /was/ in
one).

Changed test_sys's test_current_frames() so it passes with or without
thread supported compiled in.

Note that test_sys fails when Python is compiled without threads,
but for an unrelated reason (the old test_exit() fails with an
indirect ImportError on the `thread` module).  There are also
other unrelated compilation failures without threads, in extension
modules (like ctypes); at least the core compiles again.

Do we really support --without-threads?  If so, there are several
problems remaining.
diff --git a/Misc/NEWS b/Misc/NEWS
index 9fa594e..7339db2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,11 @@
   again.  Fixing this problem required changing the .pyc magic number.
   This means that .pyc files generated before 2.5c1 will be regenerated.
 
+- Bug #1524317:  Compiling Python ``--without-threads`` failed.
+  The Python core compiles again then, and, in a build without threads, the
+  new ``sys._current_frames()`` returns a dictionary with one entry,
+  mapping the faux "thread id" 0 to the current frame.
+
 Library
 -------
 
@@ -155,9 +160,9 @@
 Extension Modules
 -----------------
 
-- #1494314: Fix a regression with high-numbered sockets in 2.4.3. This 
-  means that select() on sockets > FD_SETSIZE (typically 1024) work again. 
-  The patch makes sockets use poll() internally where available. 
+- #1494314: Fix a regression with high-numbered sockets in 2.4.3. This
+  means that select() on sockets > FD_SETSIZE (typically 1024) work again.
+  The patch makes sockets use poll() internally where available.
 
 - Assigning None to pointer type fields in ctypes structures possible
   overwrote the wrong fields, this is fixed now.
@@ -1216,7 +1221,7 @@
 
 Library
 -------
-  
+
 - Patch #1388073: Numerous __-prefixed attributes of unittest.TestCase have
   been renamed to have only a single underscore prefix.  This was done to
   make subclassing easier.