extract a KeyPair from keystore

Added get-key-pair-pkcs12 function to core.clj. This function loads the keypair
from certain entry alias in a pkcs12 keystore.

This commit also adds org.clojure/tools.logging dependency to the project.
cleaning dependencies and some rogue \r
Merge pull request #1 from axs-mvd/master

extract a KeyPair from keystore