migrate to rustyline, add history support

Cargo.toml

@@ -1,14 +1,11 @@
 [package]
 name = "scryer-prolog"
-version = "0.8.93"
+version = "0.8.94"
 authors = ["Mark Thom <markjordanthom@gmail.com>"]
 repository = "https://github.com/mthom/scryer-prolog"
 description = "A modern Prolog implementation written mostly in Rust."
 license = "BSD-3-Clause"
 
-[features]
-default = ["readline_rs_compat"]
-
 [dependencies]
 cfg-if = "0.1.7"
 dirs = "2.0.2"
@@ -16,9 +13,9 @@ downcast = "0.10.0"
 indexmap = "1.0.2"
 ordered-float = "0.5.0"
 prolog_parser = "0.8.29"
-readline_rs_compat = { version = "0.1.9", optional = true }
 ref_thread_local = "0.0.0"
 rug = "1.4.0"
+rustyline = "5.0.3"
 
 [dependencies.termion]
 version = "1.4.0"