Mass rename uint/int to usize/isize

Now that support has been removed, all lingering use cases are renamed.

src/doc/trpl/ffi.md

@@ -401,7 +401,7 @@ Unsafe functions, on the other hand, advertise it to the world. An unsafe functi
 this:
 
 ```
-unsafe fn kaboom(ptr: *const int) -> int { *ptr }
+unsafe fn kaboom(ptr: *const i32) -> i32 { *ptr }
 ```
 
 This function can only be called from an `unsafe` block or another `unsafe` function.
@@ -423,7 +423,7 @@ extern {
 
 fn main() {
     println!("You have readline version {} installed.",
-             rl_readline_version as int);
+             rl_readline_version as i32);
 }
 ```
 

src/doc/trpl/more-strings.md

@@ -129,7 +129,7 @@ need, and it can make your lifetimes more complex.
 To write a function that's generic over types of strings, use `&str`.
 
 ```
-fn some_string_length(x: &str) -> uint {
+fn some_string_length(x: &str) -> usize {
     x.len()
 }