MINOR: ssl: Add the "show ssl cert foo.pem.ocsp" CLI command

Add the ability to dump an OCSP response details through a call to "show
ssl cert cert.pem.ocsp". It can also be used on an ongoing transaction
by prefixing the certificate name with a '*'.
Even if the ckch structure holds an ocsp_response buffer, we still need
to look for the actual ocsp response entry in the ocsp response tree
rather than just dumping the ckch's buffer details because when updating
an ocsp response through a "set ssl ocsp-response" call, the
corresponding buffer in the ckch is not updated accordingly. So this
buffer, even if it is not empty, might hold an outdated ocsp response.
diff --git a/doc/management.txt b/doc/management.txt
index 641f253..91c0340 100644
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -2992,6 +2992,11 @@
   certificate. This command can be useful to check if a certificate was well
   updated. You can also display details on a transaction by prefixing the
   filename by an asterisk.
+  This command can also be used to display the details of a certificate's OCSP
+  response by suffixing the filename with a ".ocsp" extension. It works for
+  committed certificates as well as for ongoing transactions. On a committed
+  certificate, this command is equivalent to calling "show ssl ocsp-response"
+  with the certificate's corresponding OCSP response ID.
 
   Example :