refactor: Make deflate enable both default implementations

Cargo.toml

@@ -68,7 +68,7 @@ aes-crypto = ["aes", "constant_time_eq", "hmac", "pbkdf2", "sha1", "rand", "zero
 chrono = ["chrono/default"]
 _deflate-any = []
 _all-features = [] # Detect when --all-features is used
-deflate = ["flate2/rust_backend", "deflate-flate2"]
+deflate = ["flate2/rust_backend", "deflate-zopfli", "deflate-flate2"]
 deflate-flate2 = ["flate2/any_impl", "_deflate-any"]
 # DEPRECATED: previously enabled `flate2/miniz_oxide` which is equivalent to `flate2/rust_backend`
 deflate-miniz = ["deflate", "deflate-flate2"]
@@ -81,7 +81,7 @@ default = [
     "aes-crypto",
     "bzip2",
     "deflate64",
-    "deflate-zlib-ng",
+    "deflate",
     "lzma",
     "time",
     "zstd",

README.md

@@ -32,12 +32,12 @@ Features
 The features available are:
 
 * `aes-crypto`: Enables decryption of files which were encrypted with AES. Supports AE-1 and AE-2 methods.
-* `deflate`: Enables decompressing the deflate compression algorithm, which is the default for zip files.
-* `deflate-zlib`: Enables deflating files with the `zlib` library (used when compression quality is 0..=9).
-* `deflate-zlib-ng`: Enables deflating files with the `zlib-ng` library (used when compression quality is 0..=9).
-  This is the fastest `deflate` implementation available.
+* `deflate`: Enables compressing and decompressing an unspecified implementation (that may change in future versions) of
+ the deflate compression algorithm, which is the default for zip files. Supports compression quality 1..=264.
+* `deflate-flate2`: Combine this with any `flate2` feature flag that enables a back-end, to support deflate compression 
+  at quality 1..=9.
 * `deflate-zopfli`: Enables deflating files with the `zopfli` library (used when compression quality is 10..=264). This
-  is the most effective `deflate` implementation available.
+  is the most effective `deflate` implementation available, but also among the slowest.
 * `deflate64`: Enables the deflate64 compression algorithm. Only decompression is supported.
 * `lzma`: Enables the LZMA compression algorithm. Only decompression is supported.
 * `bzip2`: Enables the BZip2 compression algorithm.