improved docs

Slightly improved documentation, just to make it a bit more clear.

src/main/java/org/acra/collector/ThreadCollector.java

@@ -25,11 +25,11 @@
 public class ThreadCollector {
 
     /**
-     * Collects some data identifying a Thread, usually the Thread which
-     * crashed.
+     * Convenience method that collects some data identifying a Thread, usually the Thread which
+     * crashed and returns a string containing the thread's id, name, priority and group name.
      * 
-     * @param t
-     * @return
+     * @param the thread
+     * @return a string representation of the string including the id, name and priority of the thread.
      */
     public static String collect(Thread t) {
         StringBuilder result = new StringBuilder();