OF-1448 no i18n encoded sources (#955)

* OF-1448: Encode UTF-8 i18n files during build.

* OF-1448: Keep non-encoded i18n files in source.

build/build.xml

@@ -388,6 +388,16 @@
             </else>
         </if>
 
+        <!--
+            Java has trouble reading translations from UTF-8 files. To work around that,
+            this plugin ensures that Java-compatible encoding is used.
+            See https://stackoverflow.com/questions/4659929/how-to-use-utf-8-in-resource-properties-with-resourcebundle
+          -->
+        <native2ascii encoding="UTF8" src="${target.i18n.dir}" dest="${target.i18n.dir}/encoded" />
+        <move todir="${target.i18n.dir}" overwrite="true">
+            <fileset dir="${target.i18n.dir}/encoded"/>
+        </move>
+
         <!-- Auto generates a default base i18n file -->
         <copy file="${target.i18n.dir}/${i18n.basename}_${i18n.default.locale}.properties"
               tofile="${target.i18n.dir}/${i18n.basename}.properties"/>

i18n/pom.xml

@@ -16,5 +16,26 @@
                 <directory>../src/i18n</directory>
             </resource>
         </resources>
+
+        <plugins>
+            <plugin>
+                <!--
+                    Java has trouble reading translations from UTF-8 files. To work around that,
+                    this plugin ensures that Java-compatible encoding is used.
+                    See https://stackoverflow.com/questions/4659929/how-to-use-utf-8-in-resource-properties-with-resourcebundle
+                  -->
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>native2ascii-maven-plugin</artifactId>
+                <version>1.0-beta-1</version>
+                <executions>
+                    <execution>
+                        <id>native2ascii</id>
+                        <goals>
+                            <goal>native2ascii</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
     </build>
 </project>