patch for io/wavfile.py

Hi,

I was unfortunate to discover a bug in io.wavfile, it assumes long to be 
4 bytes on all architectures and on my amd64 box I was getting errors 
reading simple wavs until I made the changes contained in the patch.  
Basically just swapped out int for long in all the struct pack and 
unpack calls where it made sense to.

--- wavfile.py	2007-09-22 00:56:31.000000000 -0700
+++ /usr/share/pyshared/scipy/io/wavfile.py	2008-08-07 13:05:12.819623113 -0700
@@ -4,7 +4,7 @@
 # assumes file pointer is immediately
 #  after the 'fmt ' id
 def _read_fmt_chunk(fid):
-    res = struct.unpack('lhHLLHH',fid.read(20))
+    res = struct.unpack('ihHIIHH',fid.read(20))
     size, comp, noc, rate, sbytes, ba, bits = res
     if (comp != 1 or size > 16):
         print "Warning:  unfamiliar format bytes..."
@@ -15,7 +15,7 @@
 # assumes file pointer is immediately 
 #   after the 'data' id
 def _read_data_chunk(fid, noc, bits):
-    size = struct.unpack('l',fid.read(4))[0]
+    size = struct.unpack('i',fid.read(4))[0]
     if bits == 8:
         data = numpy.fromfile(fid, dtype=numpy.ubyte, count=size)
         if noc > 1:
@@ -30,7 +30,7 @@