Clean up text handling a bit:

- Rename IO.write -> IO.print.
- Make IO.write not print a newline.
- Support \u Unicode escapes in strings.

test/class/equality.wren

@@ -1,13 +1,13 @@
-IO.write(Num == Num)  // expect: true
-IO.write(Num == Bool) // expect: false
+IO.print(Num == Num)  // expect: true
+IO.print(Num == Bool) // expect: false
 
 // Not equal to other types.
-IO.write(Num == 123)  // expect: false
-IO.write(Num == true) // expect: false
+IO.print(Num == 123)  // expect: false
+IO.print(Num == true) // expect: false
 
-IO.write(Num != Num)  // expect: false
-IO.write(Num != Bool) // expect: true
+IO.print(Num != Num)  // expect: false
+IO.print(Num != Bool) // expect: true
 
 // Not equal to other types.
-IO.write(Num != 123)  // expect: true
-IO.write(Num != true) // expect: true
+IO.print(Num != 123)  // expect: true
+IO.print(Num != true) // expect: true

test/class/name_inside_body.wren

@@ -1,10 +1,10 @@
 class Foo {
   static sayName {
-    IO.write(Foo.toString)
+    IO.print(Foo.toString)
   }
 
   sayName {
-    IO.write(Foo.toString)
+    IO.print(Foo.toString)
   }
 
   static toString { return "Foo!" }

test/class/new.wren

@@ -1,6 +1,6 @@
 class Foo {}
 
 var foo = new Foo
-IO.write(foo is Foo) // expect: true
+IO.print(foo is Foo) // expect: true
 
 // TODO: Test precedence and grammar of what follows "new".

test/class/type.wren

@@ -1,10 +1,10 @@
 class Foo {}
 
 // A class is a class.
-IO.write(Foo is Class) // expect: true
+IO.print(Foo is Class) // expect: true
 
 // It's metatype is also a class.
-IO.write(Foo.type is Class) // expect: true
+IO.print(Foo.type is Class) // expect: true
 
 // The metatype's metatype is Class.
-IO.write(Foo.type.type == Class) // expect: true
+IO.print(Foo.type.type == Class) // expect: true