First pass of VPF code cleanup

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>
Setup an online test to facilitate testing against large sample data

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>
untangling VPFColumn from AttributeDescriptor

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>
separate out VPFColumn from AttributeDescriptor
Initial run of tests and evaluation of codebase
Merge pull request #301 from jodygarnett/vpf_cleanup

VPF FeatureType Cleanup GEOT-2347