#358 Start refactoring PasswordSecurity

- Add new methods temporarily to NewEncrMethod interface
   - No data source access within EncryptionMethod implementations
   - Generate the salt within the EncryptionMethod implementation
- Deprecate static methods on PasswordSecurity
- Adjust AbstractEncryptionMethodTest to test the classes with the new interface
- Add getter for data source instead of accessing field directly

src/main/java/fr/xephi/authme/security/HashAlgorithm.java

@@ -3,6 +3,9 @@ package fr.xephi.authme.security;
 import fr.xephi.authme.security.crypts.EncryptionMethod;
 
 /**
+ * The list of hash algorithms supported by AuthMe. The implementing class must define a public
+ * constructor which takes either no arguments, or a DataSource object (when the salt is stored
+ * separately, writes to the database are necessary).
  */
 public enum HashAlgorithm {
 
@@ -36,7 +39,7 @@ public enum HashAlgorithm {
     SALTEDSHA512(fr.xephi.authme.security.crypts.SALTEDSHA512.class),
     CUSTOM(null);
 
-    final Class<? extends EncryptionMethod> clazz;
+    private final Class<? extends EncryptionMethod> clazz;
 
     /**
      * Constructor for HashAlgorithm.