### Fixed
- `EnvFilter` ignoring directives with targets that are the same number
of characters (#333)
- `EnvFilter` failing to properly apply filter directives to events
generated from `log` records by`tracing-log` (#344)
### Changed
- Renamed `Filter` to `EnvFilter`, deprecated `Filter` (#339)
- Renamed "filter" feature flag to "env-filter", deprecated "filter" (#339)
- `FmtSubscriber` now defaults to enabling only the `INFO` level and
above when a max level filter or `EnvFilter` is not set (#336)
### Added:
- `EnvFilter::add_directive` to add new directives to filters after they
are constructed (#334)
- `fmt::Builder::with_max_level` to set a global level filter for a
`FmtSubscriber` without requiring the use of `EnvFilter` (#336)
- `Layer` implementation for `LevelFilter` (#336)
- `EnvFilter` now implements `fmt::Display` (#329)
Signed-off-by: Eliza Weisman <eliza@buoyant.io>