Console: Add jsps to view entire router.log and wrapper.log files

Add links to /logs
Add some headers to the history.txt jsp
javadocs

core/java/src/net/i2p/util/FileLogWriter.java

@@ -37,6 +37,7 @@ class FileLogWriter extends LogWriter {
 
     /**
      *  File may not exist or have old logs in it if not opened yet
+     *  @return non-null
      */
     public synchronized String currentFile() {
         if (_currentFile != null)

core/java/src/net/i2p/util/LogManager.java

@@ -264,6 +264,10 @@ public class LogManager implements Flushable {
         loadConfig();
     }
 
+    /**
+     *  File may not exist or have old logs in it if not opened yet
+     *  @return non-null
+     */
     public String currentFile() {
         if (_writer == null)
             return ("No log file created yet");

core/java/src/net/i2p/util/LogWriter.java

@@ -37,7 +37,12 @@ abstract class LogWriter implements Runnable {
         _lastReadConfig = Clock.getInstance().now();
     }
 
+    /**
+     *  File may not exist or have old logs in it if not opened yet
+     *  @return non-null
+     */
     public abstract String currentFile();
+
     /**
      * Write the provided LogRecord to the writer.
      * @param rec the LogRecord to write.