[MNG-7231] Fix Javadoc errors

This closes #112
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-active-collection/src/main/java/org/apache/maven/plugin/coreit/CheckThreadSafetyMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-active-collection/src/main/java/org/apache/maven/plugin/coreit/CheckThreadSafetyMojo.java
index 3ce6076..972456e 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-active-collection/src/main/java/org/apache/maven/plugin/coreit/CheckThreadSafetyMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-active-collection/src/main/java/org/apache/maven/plugin/coreit/CheckThreadSafetyMojo.java
@@ -21,6 +21,7 @@
 
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
 
 import java.io.File;
 import java.io.FileOutputStream;
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-artifact/src/main/java/org/apache/maven/plugin/coreit/ResolveMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-artifact/src/main/java/org/apache/maven/plugin/coreit/ResolveMojo.java
index 09fa965..29091ef 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-artifact/src/main/java/org/apache/maven/plugin/coreit/ResolveMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-artifact/src/main/java/org/apache/maven/plugin/coreit/ResolveMojo.java
@@ -26,6 +26,7 @@
 import org.apache.maven.model.Dependency;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
 
 import java.io.File;
 import java.io.FileOutputStream;
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-log4j/src/main/java/org/apache/maven/plugin/coreit/ItMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-log4j/src/main/java/org/apache/maven/plugin/coreit/ItMojo.java
index adb8428..43600b3 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-log4j/src/main/java/org/apache/maven/plugin/coreit/ItMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-log4j/src/main/java/org/apache/maven/plugin/coreit/ItMojo.java
@@ -29,6 +29,7 @@
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
 
 /**
  * Resolves an artifact and has an (unused) dependency on log4j.
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildLocalPomMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildLocalPomMojo.java
index b7c7770..cf078b9 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildLocalPomMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildLocalPomMojo.java
@@ -21,6 +21,7 @@
 
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.project.MavenProject;
 
 import java.io.File;
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildRemotePomMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildRemotePomMojo.java
index 98cd5ef..78f2237 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildRemotePomMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-project/src/main/java/org/apache/maven/plugin/coreit/BuildRemotePomMojo.java
@@ -24,6 +24,7 @@
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.project.MavenProject;
 
 import java.io.File;