Renamed to `coll_w` and `z_coll_w` for the int and zval pointer, respectively. Also renamed `fsync` and `journal` with a `default_` prefix, so it's clear they match up with the server options.

We're already using "gle" in the `gle_op` return value and the shared zval when reading "w" and "safe" from the options array, so I didn't want to use that.