rename files, update references to them

[jakkdl]

Some straightforward search&replace after #206

[jakkdl]

All eval files are named trioXXX.py, so they should maybe all be renamed as well. Although with the given design they are written with trio as the baseline, running tests against anyio by doing search/replace on the file content. So there's a decent case for the status quo, although there are files named trio104_trio.py or trio105_anyio.py...
EDIT: I convinced myself and renamed them in a347611