Ugh, BIO_find_type() cannot be passed a NULL.

Fix doc example, and fix BIO_find_type().

Fix PKCS7_verify(). It was using 'i' for both the
loop variable and the verify return value.
diff --git a/CHANGES b/CHANGES
index 5ada535..01f8d5b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,10 @@
 
  Changes between 0.9.5a and 0.9.6  [xx XXX 2000]
 
+  *) Fix bug in PKCS7_verify() which caused an infinite loop
+     if there was more than one signature.
+     [Sven Uszpelkat <su@celocom.de>]
+
   *) Major change in util/mkdef.pl to include extra information
      about each symbol, as well as presentig variables as well
      as functions.  This change means that there's n more need