Switch PKey load/save functions to RSA specific
Switch to the more sane RSA PUBKEY function

For differences, see:
http://openssl.6102.n7.nabble.com/difference-between-i2d-PUBKEY-and-i2d-PublicKey-td43869.html

This will break loading of *public* keys generated before this commit
Merge pull request #44 from mvdnes/rsa_pubkey

Change functions used by PKey {load,save}_{pub,priv}
Allow to set cert/key pair
Update for rust rfc 52 changes
Merge pull request #48 from ebfe/rfc-52

Update for rust rfc 52 changes
Fixed documentation string
Merge pull request #47 from vhbit/cert-key-auth

Allow to set cert/key pair
Get certificate fingerprint
Merge pull request #50 from vhbit/cert-fingerprint

Get certificate fingerprint
Enabling TLS1.2 support

Unfortunately OS X comes with 0.9.8 bundled. There is a way to
install a recent version through homebrew, however it is
extremely hard to make it link agains brewed version without
tricking link version
Added TLS 1,2 with features