Bump version to 1.4-SNAPSHOT
Update to Java 7 language level (Java 6 is unsupported by Oracle)
Update Maven Compiler and Maven source plugin versions
Update dependencies to newer versions in order to fix bug #8

* Groovy 2.19 -> 2.2.2
* JAnsi 1.2.1 -> 1.11
* JLine 9.9.94 -> 2.11