Added documenntation to the docs folder and edited the mac bash script in response to tests

numpy-1.6.2/numpy/f2py/docs/usersguide/extcallback_session.dat

@@ -0,0 +1,19 @@
+>>> import pfromf
+>>> pfromf.f2()
+Traceback (most recent call last):
+  File "<stdin>", line 1, in ?
+pfromf.error: Callback fpy not defined (as an argument or module pfromf attribute).
+
+>>> def f(): print "python f"
+... 
+>>> pfromf.fpy = f
+>>> pfromf.f2()
+ in f2, calling f2py..
+python f
+>>> pfromf.f1()
+ in f1, calling f2 twice..
+ in f2, calling f2py..
+python f
+ in f2, calling f2py..
+python f
+>>>