Ensured that project data are sorted before stored, for consistency.
Added a simple download-as-json service.
Enabled upload of JSON.
Fixed a bug where patching null-keys to `/projects/:project/strings` did not actually remove the keys.
Added an option for removing tables not present in the uploaded file.
Fixed an issue where keys used for presentation bled through the download.

Updated texts used in the upload/download features.
Added ability to upload and download all project strings as JSON.