Updated documentation to be more clearly labelled

Also added placeholder for WorldMap documentation
Added code to automatically resolve duplicate file names, per #357.
More code per #357 - handling of duplicate files.
If an uploaded file appears to be a duplicate of an existing file, *by content* (i.e., by md5),
a warning message will be displayed, and the matching md5s highlighted.
This way the user has an option of either canceling the entire upload, or checking the delete
chekboxes next to the files that don't want, before they hit 'save'; or just to proceed with
adding the files as they are - if they have some kind of a weird reason to have multiple identical
files in the dataset...
Making the duplicate filename check work for subsettable files too.
and another minor cosmetic improvement for the duplicates...
Merge branch 'master' of https://github.com/IQSS/dataverse into IQSS-master

Conflicts:
	src/main/webapp/dataset.xhtml
Merge branch 'master' of https://github.com/IQSS/dataverse into IQSS-master

Conflicts:
	src/main/webapp/dataset.xhtml
Merge branch 'IQSS-master'