File upload

Adding file upload page per study. This is ready for review but note that this is not final and will need to be modified to work. Things to do are: finalize how the visualizations should work with this page, set the upload file types for each group and decide what's erasable.

Note that `resumable-uploader.js` and `resumable-uploader.js` are 3rd party libraries but `resumable-uploader.js` needed (and perhaps will need) to be modify. At this point the only changes are in the first lines of `addFile` (lines 118-124).
Well, it depends on the usage. I will say that for metadata we do not need
to store it in the DB as we decided that we will only have one valid and
copies in HD of previous ones but I agree on this about the sequences. Now,
I think that should be added once we decide/have-code to do these things.