Fixes rendering issues with upload timestamps and stagegroups with multiple stages
Fixes stage properties being overwritten in stage groups

When fetching a stage group, if the stages had parameters with the same name, the last stage would overwrite the properties of other stages with the same parameter.
Fixes rendering of string properties in the edit modal

String properties with qoutation marks got cut off at the first mark in modal input boxes.
Merge pull request #344 from laserval/fix-admin-service-gui-rendering-errors

Fix admin service gui rendering errors
Fixes typo in Admin Service readme
Makes failed stage API calls to the Core log in a more understandable way