Add SBT plugin to publish ScalaDocs
Renaming for cryptographics classes

Rename the following classes/methods in net.secloud.core.security
namespace:

* SymmetricEncryptionAlgorithm -> SymmetricAlgorithm
  * .generateKey() -> .generateParameters()
* SymmetricEncryptionMode -> SymmetricMode
* SymmetricEncryptionParameters -> SymmetricParams
Reorganize net.secloud.core.security package

Split into more files and remove CryptographicAlgorithms object. All
the inner content lives now in the net.secloud.core.security package
directly.
Merge branch 'master' into dev