#358 Handle hash + salt as one "unit"

- Rename HashResult to EncryptedPassword to reflect its broader use
- Use EncryptedPassword in methods that require the hash and the salt, instead of passing them as strings separately
- Store EncryptedPassword as field in PlayerAuth; updatePassword() thus processes the entire data in the EncryptedPassword object

src/main/java/fr/xephi/authme/security/crypts/EncryptionMethod.java

@@ -12,9 +12,9 @@ public interface EncryptionMethod {
      * @param name     The name of the player (sometimes required to generate a salt with)
      *
      * @return The hash result for the password.
-     * @see    HashResult
+     * @see    EncryptedPassword
      */
-    HashResult computeHash(String password, String name);
+    EncryptedPassword computeHash(String password, String name);
 
     /**
      * Hash the given password with the given salt for the given player.
@@ -31,14 +31,13 @@ public interface EncryptionMethod {
     /**
      * Check whether the given hash matches the clear-text password.
      *
-     * @param hash      The hash to verify
-     * @param password  The clear-text password to verify the hash against
-     * @param salt      The salt if it is stored separately (null otherwise)
-     * @param name      The player name to do the check for (sometimes required for generating the salt)
+     * @param password   The clear-text password to verify
+     * @param encryptedPassword The hash to check the password against
+     * @param name       The player name to do the check for (sometimes required for generating the salt)
      *
      * @return True if the password matches, false otherwise
      */
-    boolean comparePassword(String hash, String password, String salt, String name);
+    boolean comparePassword(String password, EncryptedPassword encryptedPassword, String name);
 
     /**
      * Generate a new salt to hash a password with.
@@ -49,7 +48,7 @@ public interface EncryptionMethod {
 
     /**
      * Return whether the encryption method requires the salt to be stored separately and
-     * passed again to {@link #comparePassword(String, String, String, String)}. Note that
+     * passed again to {@link #comparePassword(String, EncryptedPassword, String)}. Note that
      * an encryption method returning {@code false} does not imply that it uses no salt; it
      * may be embedded into the hash or it may use the username as salt.
      *