examples: Provide Maven and Gradle build files

The examples are no longer part of the normal build, although they are
built with Travis. The examples now include their own copy of the gradle
wrapper to ease usage from IDEs which can now properly detect the
correct version of gradle to use.

The build files were generated using "gradle init" and "mvn
archetype:generate" and then modified following our README.

Fixes #1414
diff --git a/examples/gradlew.bat b/examples/gradlew.bat
new file mode 100644
index 0000000..f6d5974
--- /dev/null
+++ b/examples/gradlew.bat
@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off

+@rem ##########################################################################

+@rem

+@rem  Gradle startup script for Windows

+@rem

+@rem ##########################################################################

+

+@rem Set local scope for the variables with windows NT shell

+if "%OS%"=="Windows_NT" setlocal

+

+set DIRNAME=%~dp0

+if "%DIRNAME%" == "" set DIRNAME=.

+set APP_BASE_NAME=%~n0

+set APP_HOME=%DIRNAME%

+

+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.

+set DEFAULT_JVM_OPTS=

+

+@rem Find java.exe

+if defined JAVA_HOME goto findJavaFromJavaHome

+

+set JAVA_EXE=java.exe

+%JAVA_EXE% -version >NUL 2>&1

+if "%ERRORLEVEL%" == "0" goto init

+

+echo.

+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:findJavaFromJavaHome

+set JAVA_HOME=%JAVA_HOME:"=%

+set JAVA_EXE=%JAVA_HOME%/bin/java.exe

+

+if exist "%JAVA_EXE%" goto init

+

+echo.

+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:init

+@rem Get command-line arguments, handling Windows variants

+

+if not "%OS%" == "Windows_NT" goto win9xME_args

+if "%@eval[2+2]" == "4" goto 4NT_args

+

+:win9xME_args

+@rem Slurp the command line arguments.

+set CMD_LINE_ARGS=

+set _SKIP=2

+

+:win9xME_args_slurp

+if "x%~1" == "x" goto execute

+

+set CMD_LINE_ARGS=%*

+goto execute

+

+:4NT_args

+@rem Get arguments from the 4NT Shell from JP Software

+set CMD_LINE_ARGS=%$

+

+:execute

+@rem Setup the command line

+

+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar

+

+@rem Execute Gradle

+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%

+

+:end

+@rem End local scope for the variables with windows NT shell

+if "%ERRORLEVEL%"=="0" goto mainEnd

+

+:fail

+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of

+rem the _cmd.exe /c_ return code!

+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1

+exit /b 1

+

+:mainEnd

+if "%OS%"=="Windows_NT" endlocal

+

+:omega