Reduce binary size - 9.6 -> 5.4 MiB (v0.6.0).

--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,4 +17,7 @@
 split-debuginfo = "unpacked"
 
 [profile.release]
-lto = "thin"
+lto = "fat"
+codegen-units = 1
+opt-level = "s"
+panic = "abort"