Fix source version

Fixes #94, swithced to java 7 since java 8 isnt supported on android.

BasicGameTemplate/nbproject/project.properties

@@ -49,8 +49,8 @@ javac.compilerargs=
 javac.deprecation=false
 javac.processorpath=\
     ${javac.classpath}
-javac.source=1.6
-javac.target=1.6
+javac.source=1.7
+javac.target=1.7
 javac.test.classpath=\
     ${javac.classpath}:\
     ${build.classes.dir}