Fixed several bugs from previous commits (Bad distribution of changes across multiple commits).
Introduced striping of string fields before send back as replies in main.py.
Implemented POST and DELETE calls for /artnet/metadata/category
Implemented tests for the new calls.
URL parameters are now URL decoded by the webservice
The tests now URL encode the parameters for every request.
Art2Presence relations are now creatable with POST requests to /artnet/metadata/art and listing the presences in the body.
Art2Presence tests have been introduced with relate_art.py
Also updated column name artist.description artist.name to fit a db schema update.
Added scripts to test various API calls of the webservice by creating, modifying and deleting entries from a test database of ArtNet. Do NOT use those on production.