Added checkstyle to prohibit windows line endings

Suggestion taken from jvoisin in #1121.

airsonic-main/src/main/java/org/airsonic/player/service/SearchService.java

@@ -1,75 +1,75 @@
-/*
- This file is part of Airsonic.
-
- Airsonic is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- Airsonic is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with Airsonic.  If not, see <http://www.gnu.org/licenses/>.
-
- Copyright 2016 (C) Airsonic Authors
- Based upon Subsonic, Copyright 2009 (C) Sindre Mehus
- */
-
-package org.airsonic.player.service;
-
-import org.airsonic.player.domain.Album;
-import org.airsonic.player.domain.MediaFile;
-import org.airsonic.player.domain.MusicFolder;
-import org.airsonic.player.domain.ParamSearchResult;
-import org.airsonic.player.domain.RandomSearchCriteria;
-import org.airsonic.player.domain.SearchCriteria;
-import org.airsonic.player.domain.SearchResult;
-import org.airsonic.player.service.search.IndexType;
-
-import java.util.List;
-
-/**
- * Performs Lucene-based searching.
- *
- * @author Sindre Mehus
- * @version $Id$
- * @see MediaScannerService
- */
-public interface SearchService {
-
-    SearchResult search(SearchCriteria criteria, List<MusicFolder> musicFolders,
-            IndexType indexType);
-
-    /**
-     * Returns a number of random songs.
-     *
-     * @param criteria Search criteria.
-     * @return List of random songs.
-     */
-    List<MediaFile> getRandomSongs(RandomSearchCriteria criteria);
-
-    /**
-     * Returns a number of random albums.
-     *
-     * @param count Number of albums to return.
-     * @param musicFolders Only return albums from these folders.
-     * @return List of random albums.
-     */
-    List<MediaFile> getRandomAlbums(int count, List<MusicFolder> musicFolders);
-
-    /**
-     * Returns a number of random albums, using ID3 tag.
-     *
-     * @param count Number of albums to return.
-     * @param musicFolders Only return albums from these folders.
-     * @return List of random albums.
-     */
-    List<Album> getRandomAlbumsId3(int count, List<MusicFolder> musicFolders);
-
-    <T> ParamSearchResult<T> searchByName(
-            String name, int offset, int count, List<MusicFolder> folderList, Class<T> clazz);
-
-}
+/*
+ This file is part of Airsonic.
+
+ Airsonic is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Airsonic is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Airsonic.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copyright 2016 (C) Airsonic Authors
+ Based upon Subsonic, Copyright 2009 (C) Sindre Mehus
+ */
+
+package org.airsonic.player.service;
+
+import org.airsonic.player.domain.Album;
+import org.airsonic.player.domain.MediaFile;
+import org.airsonic.player.domain.MusicFolder;
+import org.airsonic.player.domain.ParamSearchResult;
+import org.airsonic.player.domain.RandomSearchCriteria;
+import org.airsonic.player.domain.SearchCriteria;
+import org.airsonic.player.domain.SearchResult;
+import org.airsonic.player.service.search.IndexType;
+
+import java.util.List;
+
+/**
+ * Performs Lucene-based searching.
+ *
+ * @author Sindre Mehus
+ * @version $Id$
+ * @see MediaScannerService
+ */
+public interface SearchService {
+
+    SearchResult search(SearchCriteria criteria, List<MusicFolder> musicFolders,
+            IndexType indexType);
+
+    /**
+     * Returns a number of random songs.
+     *
+     * @param criteria Search criteria.
+     * @return List of random songs.
+     */
+    List<MediaFile> getRandomSongs(RandomSearchCriteria criteria);
+
+    /**
+     * Returns a number of random albums.
+     *
+     * @param count Number of albums to return.
+     * @param musicFolders Only return albums from these folders.
+     * @return List of random albums.
+     */
+    List<MediaFile> getRandomAlbums(int count, List<MusicFolder> musicFolders);
+
+    /**
+     * Returns a number of random albums, using ID3 tag.
+     *
+     * @param count Number of albums to return.
+     * @param musicFolders Only return albums from these folders.
+     * @return List of random albums.
+     */
+    List<Album> getRandomAlbumsId3(int count, List<MusicFolder> musicFolders);
+
+    <T> ParamSearchResult<T> searchByName(
+            String name, int offset, int count, List<MusicFolder> folderList, Class<T> clazz);
+
+}

checkstyle.xml

@@ -12,6 +12,12 @@
 
     <module name="FileTabCharacter"/>
 
+    <!-- This is a temporary workaround until ^M line endings is added to upstream checkstyle -->
+    <module name="RegexpMultiline">
+	<property name="format" value="\r\n"/>
+	<property name="message" value="Do not use Windows line endings"/>
+    </module>
+
     <module name="TreeWalker">
         <module name="AnnotationLocation"/>
         <module name="CustomImportOrder">