Allow Java source formatting mvn formatter:format (#4214)

Uses Eclipse formatting tools with a configuration matching Google's style guide (plus our customisations).

modules/swagger-codegen-cli/pom.xml

@@ -61,6 +61,14 @@
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>net.revelc.code</groupId>
                <artifactId>formatter-maven-plugin</artifactId>
                <configuration>
                    <!-- Point at the eclipse-formatter.xml in the swagger-codegen parent project directory -->
                    <configFile>${project.basedir}${file.separator}${project.parent.relativePath}${file.separator}eclipse-formatter.xml</configFile>
                </configuration>
            </plugin>
        </plugins>
    </build>

modules/swagger-codegen-maven-plugin/pom.xml

@@ -83,5 +83,15 @@
                </plugin>
            </plugins>
        </pluginManagement>
        <plugins>
            <plugin>
                <groupId>net.revelc.code</groupId>
                <artifactId>formatter-maven-plugin</artifactId>
                <configuration>
                    <!-- Point at the eclipse-formatter.xml in the swagger-codegen parent project directory -->
                    <configFile>${project.basedir}${file.separator}${project.parent.relativePath}${file.separator}eclipse-formatter.xml</configFile>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

modules/swagger-codegen/pom.xml

@@ -110,6 +110,14 @@
                <artifactId>maven-release-plugin</artifactId>
                 <version>2.5.3</version>
            </plugin>
            <plugin>
                <groupId>net.revelc.code</groupId>
                <artifactId>formatter-maven-plugin</artifactId>
                <configuration>
                    <!-- Point at the eclipse-formatter.xml in the swagger-codegen parent project directory -->
                    <configFile>${project.basedir}${file.separator}${project.parent.relativePath}${file.separator}eclipse-formatter.xml</configFile>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <profiles>

modules/swagger-generator/pom.xml

@@ -119,6 +119,14 @@
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>net.revelc.code</groupId>
                <artifactId>formatter-maven-plugin</artifactId>
                <configuration>
                    <!-- Point at the eclipse-formatter.xml in the swagger-codegen parent project directory -->
                    <configFile>${project.basedir}${file.separator}${project.parent.relativePath}${file.separator}eclipse-formatter.xml</configFile>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>

pom.xml

@@ -67,6 +67,26 @@
        <directory>target</directory>
        <finalName>${project.artifactId}-${project.version}</finalName>
        <plugins>
            <plugin>
                <groupId>net.revelc.code</groupId>
                <artifactId>formatter-maven-plugin</artifactId>
                <!-- Uncomment this to format before checkstyle -->
                <!-- <executions>
                    <execution>
                        <id>format</id>
                        <phase>validate</phase>
                        <goals>
                            <goal>format</goal>
                        </goals>
                    </execution>
                </executions> -->
                <configuration>
                    <compilerSource>1.7</compilerSource>
                    <compilerCompliance>1.7</compilerCompliance>
                    <compilerTargetPlatform>1.7</compilerTargetPlatform>
                    <lineEnding>LF</lineEnding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
@@ -77,6 +97,8 @@
                        <phase>validate</phase>
                        <configuration>
                            <configLocation>google_checkstyle.xml</configLocation>
                            <!-- Don't include generated sources a la http://stackoverflow.com/a/30406454 -->
                            <sourceDirectory>${project.build.sourceDirectory}</sourceDirectory>
                            <encoding>UTF-8</encoding>
                            <consoleOutput>true</consoleOutput>
                            <failsOnError>true</failsOnError>
@@ -201,6 +223,15 @@
                </executions>
            </plugin>
        </plugins>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>net.revelc.code</groupId>
                    <artifactId>formatter-maven-plugin</artifactId>
                    <version>0.5.2</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
    <profiles>
        <profile>