If a value for a placeholder needs escaping, add the character to
escape with an "^" to the name of the placeholder, e.g. {memfs^:}.
This will escape all occurences of ":" in the value for {memfs}
with a "\".
If PUT /process/:id is called in order to replace an existing
process config with an invalid process config, the existing
process was deleted and an 409 was returned. A subsequent GET on
the previous process would then return a 404, which is not
what you expect. The previous process needs to stay in place.
