std: Deprecate a number of unstable features

Many of these have long since reached their stage of being obsolete, so this
commit starts the removal process for all of them. The unstable features that
were deprecated are:

* cmp_partial
* fs_time
* hash_default
* int_slice
* iter_min_max
* iter_reset_fuse
* iter_to_vec
* map_in_place
* move_from
* owned_ascii_ext
* page_size
* read_and_zero
* scan_state
* slice_chars
* slice_position_elem
* subslice_offset

src/libstd/ascii.rs

@@ -20,6 +20,9 @@ use mem;
 /// Extension methods for ASCII-subset only operations on owned strings
 #[unstable(feature = "owned_ascii_ext",
            reason = "would prefer to do this in a more general way")]
+#[deprecated(since = "1.3.0",
+             reason = "hasn't yet proved essential to be in the standard library")]
+#[allow(deprecated)]
 pub trait OwnedAsciiExt {
     /// Converts the string to ASCII upper case:
     /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
@@ -164,11 +167,13 @@ impl AsciiExt for str {
     }
 
     #[inline]
+    #[allow(deprecated)]
     fn to_ascii_uppercase(&self) -> String {
         self.to_string().into_ascii_uppercase()
     }
 
     #[inline]
+    #[allow(deprecated)]
     fn to_ascii_lowercase(&self) -> String {
         self.to_string().into_ascii_lowercase()
     }
@@ -189,6 +194,7 @@ impl AsciiExt for str {
     }
 }
 
+#[allow(deprecated)]
 impl OwnedAsciiExt for String {
     #[inline]
     fn into_ascii_uppercase(self) -> String {
@@ -212,11 +218,13 @@ impl AsciiExt for [u8] {
     }
 
     #[inline]
+    #[allow(deprecated)]
     fn to_ascii_uppercase(&self) -> Vec<u8> {
         self.to_vec().into_ascii_uppercase()
     }
 
     #[inline]
+    #[allow(deprecated)]
     fn to_ascii_lowercase(&self) -> Vec<u8> {
         self.to_vec().into_ascii_lowercase()
     }
@@ -242,6 +250,7 @@ impl AsciiExt for [u8] {
     }
 }
 
+#[allow(deprecated)]
 impl OwnedAsciiExt for Vec<u8> {
     #[inline]
     fn into_ascii_uppercase(mut self) -> Vec<u8> {