Update JRE/JDK to Java 7

This closes #193. This should eliminate Eclipse warnings for developers
who don't have a version 5 and 6 JRE or JDK on their systems (but
hopefully have version 7 JDK.)
Infer type parameters of constructors

This should silence potential warnings and make the code more robust
in the face of future changes.
Use try-resource management

This should drastically simplify resource management code, eliminate
warnings, and ensure resources aren't being leaked.