updated all the maven plugins to their latest versions

Update List:
1) Maven Compiler (2.3.2 to 3.1)
2) Maven SCM (1.7 to 1.9)
3) ANTLR v3 (3.5.1 to 3.5.2) - (Minor update to get rid of Java JDK 8 warnings)
4) JUnit (4.8.1 to 4.11)