DevText store: create/write permissions mixed

[mahemoff]

I believe the dev text store may be incorrectly forbidding "create" operations.

Unfortunately, I don't have an isolated test case; I'm seeing it with comments plugin. It returns 403 when the browser PUTs a new tiddler with the message "(user" cannot write). I change the "write" permissions to allow the user to write and it's fine. However, "write" should not matter in this case; "create" should matter.

[cdent]

invalid with rearchitecture of devstore