Use @Exported annotation in ProGuard.

Change-Id: I2d805d5437e8b83d58a1b3e4c0ea35ec4599238f
Reviewed-on: http://gerrit.dmdirc.com/2914
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

build-reports.xml

@@ -179,11 +179,7 @@
 
             <!-- Exported services -->
             -keepclassmembers class ** implements com.dmdirc.plugins.Plugin {
-                <!-- Parsers -->
-                public com.dmdirc.parser.interfaces.Parser getParser(com.dmdirc.parser.common.MyInfo,java.net.URI);
-                public com.dmdirc.parser.interfaces.ProtocolDescription getDescription();
-                <!-- Tab completers -->
-                public com.dmdirc.ui.input.tabstyles.TabCompletionStyle getCompletionStyle(com.dmdirc.ui.input.TabCompleter,com.dmdirc.WritableFrameContainer);
+                @com.dmdirc.plugins.Exported &lt;methods&gt;;
             }
 
             <!-- Debug plugin commands -->