Merge pull request #33 from kpartlow/master

Updated Compiler to require Java 1.7 source and target.
cleaned up error messages
simplified error handling
Added try-with-resources for ResultSet, too.
Updated error reporting on connection validation.
- bug fix: Groovy code is now reloaded properly (all internal caches cleared)
- bug fix: An exception was swallowed in NCubeManager when a bad URL was passed into setBaseResourceUrls()
- bug fix: When a URL fails to resolve (null is returned), the URL, ncube, and n-cube version are given in an IllegalStateException, rather than an NPE occurring.
[maven-release-plugin] prepare release 2.7.4.201407230130
[maven-release-plugin] prepare for next development iteration
Updated for John's changes