OntoString mappings need to be written back to Zooma

[henrietteharmse]

For this each project will need to be able to configure a single data source on Zooma which needs to be updated with this information.

A potential issue is that currently Zooma data sources are overwritten with every data release. As an example, consider GWAS. Currently OntoString reads the GWAS datasource of Zooma and uses this information update mappings of the GWAS project on OntoString. We can export these mappings to Zooma, but there may be mappings in Zooma that is not in OntoString. Thus, writing back mappings to Zooma from OntoString directly to the GWAS datasource on Zooma can cause Zooma to loose data.