Improve MAVEN build Performance

[ChenZhangg]

Parallel builds in Maven 3 Maven 3.x has the capability to perform parallel builds.

Apache Maven Dependency Plugin can be used to find unused dependencies. And I found following list. Maybe we can remove them.
ninja
ninja-core
{groupId='com.google.inject.extensions', artifactId='guice-assistedinject'}
{groupId='org.slf4j', artifactId='jcl-over-slf4j'}
{groupId='org.slf4j', artifactId='log4j-over-slf4j'}
{groupId='org.hibernate', artifactId='hibernate-validator'}
{groupId='com.fasterxml.woodstox', artifactId='woodstox-core'}
{groupId='org.flywaydb', artifactId='flyway-core'}
{groupId='com.google.inject.extensions', artifactId='guice-persist'}
{groupId='org.hibernate', artifactId='hibernate-entitymanager'}
{groupId='org.hibernate', artifactId='hibernate-c3p0'}
{groupId='org.powermock', artifactId='powermock-module-junit4'}
{groupId='org.powermock', artifactId='powermock-api-mockito2'}
{groupId='javax.xml.bind', artifactId='jaxb-api'}
ninja-postoffice
{groupId='org.mockito', artifactId='mockito-core'}
ninja-websockets-jsr356
ninja-servlet
ninja-standalone
{groupId='javax.websocket', artifactId='javax.websocket-api'}
ninja-db-classic
ninja-test-utilities
{groupId='org.ninjaframework', artifactId='ninja-standalone'}
{groupId='org.hamcrest', artifactId='java-hamcrest'}
{groupId='org.seleniumhq.selenium', artifactId='htmlunit-driver'}
{groupId='org.eclipse.jetty', artifactId='jetty-client'}
{groupId='org.eclipse.jetty.websocket', artifactId='websocket-client'}
ninja-jaxy-routes
{groupId='org.ninjaframework', artifactId='ninja-test-utilities'}
ninja-metrics
ninja-metrics-graphite
ninja-metrics-ganglia
{groupId='junit', artifactId='junit'}
{groupId='org.mockito', artifactId='mockito-core'}
ninja-metrics-librato
{groupId='junit', artifactId='junit'}
{groupId='org.mockito', artifactId='mockito-core'}
ninja-metrics-influxdb
{groupId='junit', artifactId='junit'}
{groupId='org.mockito', artifactId='mockito-core'}
ninja-maven-plugin
{groupId='org.apache.maven', artifactId='maven-compat'}
ninja-servlet-integration-test
{groupId='org.webjars', artifactId='bootstrap'}
{groupId='org.mindrot', artifactId='jbcrypt'}
ninja-servlet-jpa-blog-integration-test
{groupId='org.webjars', artifactId='tinymce-jquery'}
{groupId='org.webjars', artifactId='bootstrap'}
{groupId='com.h2database', artifactId='h2'}
{groupId='org.ninjaframework', artifactId='ninja-servlet'}
ninja-servlet-jpa-blog-archetype
ninja-servlet-archetype-simple

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If there are any inappropriate modifications in this PR, please give me a reply and I will change them.