Add support for default PHP padding : "OPENSSL_PKCS1_PADDING"

[mgcrea]

Would be awesome as i'm stuck on this on a project (using PHP on the server side).
PHP : http://php.net/manual/en/function.openssl-public-encrypt.php

Tried to manually replace occurrences of OPENSSL_PKCS1_PADDING with it.

But i get a build error node-waf configure build :

../node_rsa.cc:310: error: ‘OPENSSL_PKCS1_PADDING’ was not declared in this scope

[mgcrea]

Already done there :
https://github.com/elaberge/node-rsa/commit/6ea783279fba6bd21debe866544f7d4c73ae1ce8

Pull request?