Change delayed injection to only change behavior of its own elements

- Introduce new BeforeInjecting annotation to not modify the (expected) order of annotations that do not belong to us
  - Avoids using hacky way of first initializing field to an Answer that will delegate on demand to the proper class...
- Remove PostConstruct support for Mockito's InjectMocks: we should not change the established behavior of external elements

src/test/java/fr/xephi/authme/command/CommandMapperTest.java

@@ -1,15 +1,15 @@
 package fr.xephi.authme.command;
 
-import fr.xephi.authme.DelayedInject;
-import fr.xephi.authme.DelayedInjectionRunner;
 import fr.xephi.authme.command.TestCommandsUtil.TestLoginCommand;
 import fr.xephi.authme.command.TestCommandsUtil.TestRegisterCommand;
 import fr.xephi.authme.command.TestCommandsUtil.TestUnregisterCommand;
 import fr.xephi.authme.command.executable.HelpCommand;
 import fr.xephi.authme.permission.PermissionNode;
 import fr.xephi.authme.permission.PermissionsManager;
+import fr.xephi.authme.runner.BeforeInjecting;
+import fr.xephi.authme.runner.InjectDelayed;
+import fr.xephi.authme.runner.DelayedInjectionRunner;
 import org.bukkit.command.CommandSender;
-import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -41,7 +41,7 @@ public class CommandMapperTest {
 
     private static Set<CommandDescription> commands;
 
-    @DelayedInject
+    @InjectDelayed
     private CommandMapper mapper;
 
     @Mock
@@ -55,7 +55,7 @@ public class CommandMapperTest {
         commands = TestCommandsUtil.generateCommands();
     }
 
-    @Before
+    @BeforeInjecting
     public void setUpMocks() {
         given(commandInitializer.getCommands()).willReturn(commands);
     }