RFR 8138653: Default key sizes for the AlgorithmParameterGenerator and KeyPairGenerator implementations should be upgraded

[Sean Mullan]

Please review this fix to improve security defaults by increasing the 
default keysize of the RSA, DSA, and DiffieHellman implementations of 
AlgorithmParameterGenerator and KeyPairGenerator from 1024 to 2048 bits:

http://cr.openjdk.java.net/~mullan/webrevs/8138653/webrev.00/
Thanks,
Sean