std: Rename {Eq,Ord} to Partial{Eq,Ord}

This is part of the ongoing renaming of the equality traits. See #12517 for more
details. All code using Eq/Ord will temporarily need to move to Partial{Eq,Ord}
or the Total{Eq,Ord} traits. The Total traits will soon be renamed to {Eq,Ord}.

cc #12517

[breaking-change]
diff --git a/src/libcollections/ringbuf.rs b/src/libcollections/ringbuf.rs
index f45c968..0ca4177 100644
--- a/src/libcollections/ringbuf.rs
+++ b/src/libcollections/ringbuf.rs
@@ -364,7 +364,7 @@
     }
 }
 
-impl<A: Eq> Eq for RingBuf<A> {
+impl<A: PartialEq> PartialEq for RingBuf<A> {
     fn eq(&self, other: &RingBuf<A>) -> bool {
         self.nelts == other.nelts &&
             self.iter().zip(other.iter()).all(|(a, b)| a.eq(b))
@@ -397,7 +397,7 @@
     use self::test::Bencher;
     use deque::Deque;
     use std::clone::Clone;
-    use std::cmp::Eq;
+    use std::cmp::PartialEq;
     use std::fmt::Show;
     use super::RingBuf;
 
@@ -483,7 +483,7 @@
     }
 
     #[cfg(test)]
-    fn test_parameterized<T:Clone + Eq + Show>(a: T, b: T, c: T, d: T) {
+    fn test_parameterized<T:Clone + PartialEq + Show>(a: T, b: T, c: T, d: T) {
         let mut deq = RingBuf::new();
         assert_eq!(deq.len(), 0);
         deq.push_front(a.clone());
@@ -568,21 +568,21 @@
         })
     }
 
-    #[deriving(Clone, Eq, Show)]
+    #[deriving(Clone, PartialEq, Show)]
     enum Taggy {
         One(int),
         Two(int, int),
         Three(int, int, int),
     }
 
-    #[deriving(Clone, Eq, Show)]
+    #[deriving(Clone, PartialEq, Show)]
     enum Taggypar<T> {
         Onepar(int),
         Twopar(int, int),
         Threepar(int, int, int),
     }
 
-    #[deriving(Clone, Eq, Show)]
+    #[deriving(Clone, PartialEq, Show)]
     struct RecCy {
         x: int,
         y: int,