Fixes spelling (includes one API change)

Mostly benign changes. Added one new method to replace a method with a spelling mistake in its name. Kept the old method, marked as 'deprecated'.

smack-java8-full/src/main/java/org/jivesoftware/smackx/SmackExtensions.java

@@ -18,7 +18,7 @@ package org.jivesoftware.smackx;
 
 /**
  * This is just a dummy class, please head over to {@link org.jivesoftware.smackx} for more information on Smack
- * extensions. The dummy class causes javadoc generate the HTML for smackx.pacakge-info.java, which would otherwise be
+ * extensions. The dummy class causes javadoc generate the HTML for smackx.package-info.java, which would otherwise be
  * not generated, as org.jivesoftware.smackx is an empty package (see
  * <a href="https://bugs.openjdk.org/browse/JDK-4492654">JDK-4492654</a>).
  */

smack-java8-full/src/main/java/org/jivesoftware/smackx/package-info.java

@@ -71,7 +71,7 @@
  * <td>Extended Stanza Addressing</td>
  * <td><a href="https://xmpp.org/extensions/xep-0033.html">XEP-0033</a></td>
  * <td></td>
- * <td>Allows to include headers in stanzas in order to specifiy multiple recipients or sub-addresses.</td>
+ * <td>Allows to include headers in stanzas in order to specify multiple recipients or sub-addresses.</td>
  * </tr>
  * <tr>
  * <td>Multi User Chat</td>
@@ -477,7 +477,7 @@
  * <td>Data Forms Geolocation Element</td>
  * <td><a href="https://xmpp.org/extensions/xep-0350.html">XEP-0350</a></td>
  * <td></td>
- * <td>Allows to include XEP-0080 gelocation data in XEP-0004 data forms.</td>
+ * <td>Allows to include XEP-0080 geolocation data in XEP-0004 data forms.</td>
  * </tr>
  * <tr>
  * <td>Client State Indication</td>