Move egui/math into new crate emath

emath/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "emath"
+version = "0.7.0"
+authors = ["Emil Ernerfeldt <emil.ernerfeldt@gmail.com>"]
+description = "Minimal 2D math library for GUI work"
+edition = "2018"
+homepage = "https://github.com/emilk/egui"
+license = "MIT OR Apache-2.0"
+readme = "README.md"
+repository = "https://github.com/emilk/egui"
+categories = ["gui", "math"]
+keywords = ["gui", "math"]
+include = [
+  "**/*.rs",
+  "Cargo.toml",
+]
+
+[lib]
+
+[dependencies]
+serde = { version = "1", features = ["derive"], optional = true }
+
+[features]
+default = []