VCF Upload UI

[mjshepherd]

This is a big feature that will be needed for proper integration into PhenoTips. It includes:

• A file upload interface, similar to the image uploader currently used by PhenoTips.
• An interface to allow users to control the VCF in the variant store (ie remove a vcf file from a patient record)
• A notification system which will alert users once their VCF file has been processed and ready for querying. Currently two things happen when the variant store process completes, the api will fire an java VCFUploadCompleteEvent and change the status property of the VCFStatus object to "done". One possible way to notify users would be to publish events to the xwiki event stream and place a gadget on the home page displaying the event stream. This approach is related to phenotips/phenotips#1525 and will require changes in the main phenotips repository.