Fixing the way _id is gotten from the markers for advanced compilation
Merge pull request #999 from onaio/998_advanced_compilation_fixes

Fixing the way _id is gotten from the markers for advanced compilation
GM: Added XLS Report selectors to dataset show template
GM: Added xls-report upload functionality
GM/RR: Implemented XLS Template posting to j2x service
GM: Added xls report upload form
GM: Add metadata api endpoint with xls-report export url
GM: Added display of available xls reports
GM: [WIP] Downloading of XLS Reports from j2x
GM: Finished XLS report download implementation
GM: Fixed failing test
GM: xls report list is updated asyncly when new report is added
GM: Implemented xls-report deleting
GM: Added test for xls-template-upload
GM: Added GET xls-report route test
GM/RR: Added POST route tests for xls reports
GM/RR added tests for upload-xls-template api fn
GM/RR Test add-xls-report api call
GM/RR Added test for downloading xls report api
GM: Added parse-http tests