partial revert of 47e3343 to add root modules back

net.sf.eclipsecs.checkstyle/metadata/com/puppycrawl/tools/checkstyle/checkstyle-metadata.properties

@@ -1 +1,16 @@
 Other.group = Other
+
+Checker.name           = Checker
+Checker.desc           = Root module of every checkstyle configuration. Cannot be deleted.
+Checker.cacheFile      = caches information about files that have checked ok; used to avoid repeated checks of the same files
+Checker.basedir        = base directory name; stripped off in messages about files
+Checker.localeCountry  = locale country for messages
+Checker.localeLanguage = locale language for messages
+Checker.charset        = name of the file charset (Note: eclipse-cs plugin sets this property to the projects default charset)
+Checker.fileExtensions = file extensions that are accepted (comma separated)
+Checker.haltOnException = Controls whether exceptions should halt execution or not.
+Checker.tabWidth       = number of expanded spaces for a tab character ('\t'); used in messages and Checks that print violations on files with tabs
+
+TreeWalker.name           = TreeWalker
+TreeWalker.desc           = FileSetCheck TreeWalker checks individual Java source files and defines properties that are applicable to checking such files.
+TreeWalker.fileExtensions = file type extension to identify java files. Setting this property is typically only required if your java source code is preprocessed before compilation and the original files do not have the extension .java

net.sf.eclipsecs.checkstyle/metadata/com/puppycrawl/tools/checkstyle/checkstyle-metadata.xml

@@ -4,5 +4,43 @@
 "http://eclipse-cs.sourceforge.net/dtds/checkstyle-metadata_1_1.dtd">
 <checkstyle-metadata>
     <rule-group-metadata name="%Other.group" priority="1500">
+
+        <rule-metadata name="%Checker.name" internal-name="Checker" parent="Root" singleton="true" default-severity="warning">
+            <alternative-name internal-name="com.puppycrawl.tools.checkstyle.Checker"/>
+            <description>%Checker.desc</description>
+            <property-metadata name="cacheFile" datatype="File">
+                <description>%Checker.cacheFile</description>
+            </property-metadata>
+            <property-metadata name="basedir" datatype="String">
+                <description>%Checker.basedir</description>
+            </property-metadata>
+            <property-metadata name="localeCountry" datatype="String">
+                <description>%Checker.localeCountry</description>
+            </property-metadata>
+            <property-metadata name="localeLanguage" datatype="String">
+                <description>%Checker.localeLanguage</description>
+            </property-metadata>
+            <property-metadata name="charset" datatype="String">
+                <description>%Checker.charset</description>
+            </property-metadata>
+            <property-metadata name="fileExtensions" datatype="String">
+                <description>%Checker.fileExtensions</description>
+            </property-metadata>
+            <property-metadata name="haltOnException" datatype="Boolean" default-value="true">
+                <description>%Checker.haltOnException</description>
+            </property-metadata>
+            <property-metadata name="tabWidth" datatype="Integer" default-value="8">
+                <description>%Checker.tabWidth</description>
+            </property-metadata>
+        </rule-metadata>
+
+        <rule-metadata name="%TreeWalker.name" internal-name="TreeWalker" parent="Checker"
+            singleton="true">
+            <alternative-name internal-name="com.puppycrawl.tools.checkstyle.TreeWalker"/>
+            <description>%TreeWalker.desc</description>
+            <property-metadata name="fileExtensions" datatype="String" default-value="java">
+                <description>%TreeWalker.fileExtensions</description>
+            </property-metadata>
+        </rule-metadata>
     </rule-group-metadata>
 </checkstyle-metadata>

net.sf.eclipsecs.checkstyle/test/net/sf/eclipsecs/checkstyle/ChecksTest.java

@@ -21,10 +21,19 @@
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 
+import com.puppycrawl.tools.checkstyle.Checker;
+import com.puppycrawl.tools.checkstyle.TreeWalker;
+
 public class ChecksTest {
+
   @Test
   public void testMetadataFiles() throws Exception {
     final Set<Class<?>> modules = CheckUtil.getCheckstyleModules();
+
+    // don't test root modules
+    modules.remove(Checker.class);
+    modules.remove(TreeWalker.class);
+
     final Set<String> packages = CheckUtil.getPackages(modules);
 
     assertTrue(modules.size() > 0, "no modules");