chore(pmd): enable some new rules from PMD 6.0.0

Quotes from https://pmd.github.io/2017/12/15/PMD-6.0.0/#new-rules
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The new Java rule DoNotExtendJavaLangThrowable (category errorprone) is a companion for the
java-strictexception.xml/DoNotExtendJavaLangError, detecting direct extensions of
java.lang.Throwable.

The new Java rule ForLoopCanBeForeach (category errorprone) helps to identify those for-loops that
can be safely refactored into for-each-loops available since java 1.5.

The new Java rule AvoidFileStream (category performance) helps to identify code relying on
FileInputStream / FileOutputStream which, by using a finalizer, produces extra / unnecessary
overhead to garbage collection, and should be replaced with Files.newInputStream /
Files.newOutputStream available since java 1.7.

The new Java rule DataClass (category design) detects simple data-holders without behaviour. This
might indicate that the behaviour is scattered elsewhere and the data class exposes the internal
data structure, which breaks encapsulation.
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Note that DataClass rule is disabled because we use data classes extensively.

Author: php-coder

src/main/config/pmd.xml

@@ -20,6 +20,7 @@
 	<rule ref="category/java/bestpractices.xml/CheckResultSet" />
 	<rule ref="category/java/bestpractices.xml/ConstantsInInterface" />
 	<rule ref="category/java/bestpractices.xml/DefaultLabelNotLastInSwitchStmt" />
+	<rule ref="category/java/bestpractices.xml/ForLoopCanBeForeach" />
 	<!--<rule ref="category/java/bestpractices.xml/JUnit4SuitesShouldUseSuiteAnnotation" />-->
 	<rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseAfterAnnotation" />
 	<rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseBeforeAnnotation" />
@@ -138,6 +139,7 @@
 	<rule ref="category/java/design.xml/CouplingBetweenObjects" />
 	<!-- We use ModifiedCyclomaticComplexity -->
 	<!--<rule ref="category/java/design.xml/CyclomaticComplexity" />-->
+	<!--<rule ref="category/java/design.xml/DataClass" />-->
 	<rule ref="category/java/design.xml/DoNotExtendJavaLangError" />
 	<rule ref="category/java/design.xml/ExceptionAsFlowControl" />
 	<rule ref="category/java/design.xml/ExcessiveClassLength" />
@@ -208,6 +210,7 @@
 	<!--<rule ref="category/java/errorprone.xml/DataflowAnomalyAnalysis" />-->
 	<rule ref="category/java/errorprone.xml/DoNotCallGarbageCollectionExplicitly" />
 	<rule ref="category/java/errorprone.xml/DoNotCallSystemExit" />
+	<rule ref="category/java/errorprone.xml/DoNotExtendJavaLangThrowable" />
 	<rule ref="category/java/errorprone.xml/DoNotThrowExceptionInFinally" />
 	<rule ref="category/java/errorprone.xml/DontImportSun" />
 	<rule ref="category/java/errorprone.xml/DontUseFloatTypeForLoopIndices" />
@@ -281,6 +284,7 @@
 	<rule ref="category/java/performance.xml/AddEmptyString" />
 	<rule ref="category/java/performance.xml/AppendCharacterWithChar" />
 	<rule ref="category/java/performance.xml/AvoidArrayLoops" />
+	<rule ref="category/java/performance.xml/AvoidFileStream" />
 	<rule ref="category/java/performance.xml/AvoidInstantiatingObjectsInLoops" />
 	<rule ref="category/java/performance.xml/AvoidUsingShortType" />
 	<rule ref="category/java/performance.xml/BigIntegerInstantiation" />