Quick patch to add a function openssl_csr_subject() that allows you to
see the subject of a CSR. Uses the same CSR handling routines as
openssl_csr_sign() etc, so it can take a string in PEM format, a file,
whatever.
Prototype: string openssl_csr_subject(mixed csr)
Sample return value:
string(99) "/C=CA/ST=Ontario/L=Kingston/O=Greg MacLellan/OU=PHP/CN=CSR
Test/emailAddress=greg@gregmaclellan.com"
