travis: fix buffer overflow in Java_java_net_Inet4AddressImpl_getLocalHostName of OpenJDK6 and OpenJDK7 when using precise distribution
travis: fix buffer overflow in Java_java_net_Inet4AddressImpl_getLocalHostName of OpenJDK6 and OpenJDK7 when using precise distribution

To fix this use the current (trusty) distribution and manually install openjdk-6-jdk and a java 6 compatible maven version. (closes #11)

(side effect: close #9)

apache/commons-fileupload,apache/commons-fileupload