Enable more 'checkstyle' checks

AvoidStarImport
IllegalImport
RedundantImport
UpperEll
ArrayTypeStyle
GenericWhitespace
EmptyStatement
PackageDelcaration

config/checkstyle.xml

@@ -22,7 +22,6 @@
 		<module name="UnusedImports">
 			<property name="processJavadoc" value="true"/>
 		</module>
-		<!-- TODO: enable later on
 		<module name="AvoidStarImport"/>
 		<module name="IllegalImport"/>
 		<module name="RedundantImport"/>
@@ -31,6 +30,5 @@
 		<module name="GenericWhitespace"/>
 		<module name="EmptyStatement"/>
 		<module name="PackageDeclaration"/>
-		-->
 	</module>
 </module>

config/suppressions.xml

@@ -3,5 +3,11 @@
     "-//Puppy Crawl//DTD Suppressions 1.1//EN"
     "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
 <suppressions>
-	<!-- currently none -->
+	<suppress checks="IllegalImport"
+			  files="Java7HostnameVerifier.java"/>
+	<!-- GenericWhitespace has some problems with false postive, leave
+it disabled until gradle uses a checkstyle version where this is fixed
+-->
+	<suppress checks="GenericWhitespace"
+			  files="Protocol.java" />
 </suppressions>