Merge pull request #591 from bader/typo-fix

Fix typo in multi_ptr class name

adoc/chapters/what_changed.adoc

@@ -387,7 +387,7 @@ Changes in [code]#multi_ptr# interface:
  * [code]#global_ptr#, [code]#local_ptr# and [code]#private_ptr# alias take the
  new extra parameter;
  * addition of the [code]#address_space_cast# free function to cast undecorated
- pointer to [code]#multi_pointer#;
+ pointer to [code]#multi_ptr#;
  * addition of construction/conversion operator for the generic address space;
  * removal of the constructor and assignment operator taking an unannotated
  pointer;