Fix some typos in tutorial

Author: marijnh

doc/tutorial/ffi.md

@@ -1,6 +1,6 @@
 # Interacting with foreign code
 
-On of Rust's aims, as a system programming language, is to
+One of Rust's aims, as a system programming language, is to
 interoperate well with C code.
 
 We'll start with an example. It's a bit bigger than usual, and

doc/tutorial/func.md

@@ -61,6 +61,8 @@ stored in data structures or returned.
 A block with no arguments is written `{|| body(); }`—you can not leave
 off the pipes.
 
+FIXME mention bind
+
 ## Iteration
 
 Functions taking blocks provide a good way to define non-trivial

doc/tutorial/mod.md

@@ -1,7 +1,7 @@
 # Modules and crates
 
-The Rust namespace is divided in modules. Each source file starts with
-its own, empty module.
+The Rust namespace is divided into modules. Each source file starts
+with its own, empty module.
 
 ## Local modules
 
@@ -153,7 +153,7 @@ restricted with `export` directives at the top of the module or file.
 
 This defines a rock-solid encryption algorithm. Code outside of the
 module can refer to the `enc::encrypt` and `enc::decrypt` identifiers
-just fine, but it does not have access to `enc::syper_secret_number`.
+just fine, but it does not have access to `enc::super_secret_number`.
 
 ## Namespaces
 
@@ -185,10 +185,10 @@ context.
 Identifiers can shadow each others. In this program, `x` is of type
 `int`:
 
-    type x = str;
+    type t = str;
     fn main() {
-        type x = int;
-        let x: int;
+        type t = int;
+        let x: t;
     }
 
 An `import` directive will only import into the namespaces for which

doc/tutorial/syntax.md

@@ -35,7 +35,7 @@ like `if` and `while` are available:
 
 ## Expression syntax
 
-Though it isn't apparent in most everyday code, there is a fundamental
+Though it isn't apparent in all code, there is a fundamental
 difference between Rust's syntax and the predecessors in this family
 of languages. A lot of thing that are statements in C are expressions
 in Rust. This allows for useless things like this (which passes