Bunch of work on types

- Comment out a bunch of types modules for now
- Implement fmt::Display on Object (this breaks the build because Number doesn't
  implement Display yet)
- Move all the Is* traits to predicates.rs

Haven't run tests yet because they won't build...

types/src/predicates.rs

@@ -0,0 +1,31 @@
+/* types/src/predicates.rs
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+pub trait IsNull {
+    /// Is this thing null?
+    fn is_null(&self) -> bool { false }
+}
+
+pub trait IsBool {
+    /// Is this thing a boolean?
+    fn is_bool(&self) -> bool { false }
+}
+
+pub trait IsChar {
+    /// Is this thing a char?
+    fn is_char(&self) -> bool { false }
+}
+
+pub trait IsNumber {
+    /// Is this thing a number?
+    fn is_number(&self) -> bool { self.is_complex() || self.is_real() || self.is_rational() || self.is_integer() }
+    /// Should return `true` if this Value is a complex number type.
+    fn is_complex(&self) -> bool { self.is_real() }
+    /// Should return `true` if this Value is a real number type.
+    fn is_real(&self) -> bool { self.is_rational() }
+    /// Should return `true` if this Value is a rational number type.
+    fn is_rational(&self) -> bool { self.is_integer() }
+    /// Should return `true` if this Value is a integer number type.
+    fn is_integer(&self) -> bool { false }
+}