Minor - Javadoc changes

- Add/replace/improve javadoc in the commands and encryption section
- Note: A simple <p> is the javadoc way to make a new paragraph
http://www.oracle.com/technetwork/java/javase/documentation/index-137868.html#format
- Note: Do not escape '<' and '>' inside of {@code }
- Note: '>' does not need to be escaped

src/main/java/fr/xephi/authme/security/crypts/description/AsciiRestricted.java

@@ -6,7 +6,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Denotes an encryption algorithm that is restricted to the ASCII charset.
+ * Denotes a hashing algorithm that is restricted to the ASCII charset.
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)

src/main/java/fr/xephi/authme/security/crypts/description/HasSalt.java

@@ -13,13 +13,17 @@ import java.lang.annotation.Target;
 @Retention(RetentionPolicy.RUNTIME)
 public @interface HasSalt {
 
-    /** The type of the salt.
-     * @return salttype The SaltType
+    /**
+     * The type of the salt.
+     *
+     * @return The salt type
      */
     SaltType value();
 
-    /** For text salts, the length of the salt.
-     * @return int Integer
+    /**
+     * For text salts, the length of the salt.
+     *
+     * @return The length of the salt the algorithm uses, or 0 if not defined or not applicable.
      */
     int length() default 0;
 

src/main/java/fr/xephi/authme/security/crypts/description/Recommendation.java

@@ -6,14 +6,18 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Annotation to mark a hash algorithm with the usage recommendation, see {@link Usage}.
+ * Annotation to mark a hash algorithm with the usage recommendation.
+ *
+ * @see Usage
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Recommendation {
 
-    /** The recommendation for using the hash algorithm.
-     * @return Usage The Usage
+    /**
+     * The recommendation for using the hash algorithm.
+     *
+     * @return The recommended usage
      */
     Usage value();
 

src/main/java/fr/xephi/authme/security/crypts/description/SaltType.java

@@ -8,7 +8,7 @@ public enum SaltType {
     /** Random, newly generated text. */
     TEXT,
 
-    /** Salt is based on the username, including variations and repetitions. */
+    /** Salt is based on the username, including variations and repetitions thereof. */
     USERNAME,
 
     /** No salt. */

src/main/java/fr/xephi/authme/security/crypts/description/Usage.java

@@ -2,6 +2,12 @@ package fr.xephi.authme.security.crypts.description;
 
 /**
  * Usage recommendation that can be provided for a hash algorithm.
+ * <p>
+ * Use the following rules of thumb:
+ * <ul>
+ *     <li>Hashes using MD5 may be {@link #ACCEPTABLE} but never {@link #RECOMMENDED}.</li>
+ *     <li>Hashes using no salt or one based on the username should be {@link #DO_NOT_USE}.</li>
+ * </ul>
  */
 public enum Usage {