Recover current view from state after SST.

When member joins the group and needs to receive an SST it won't
receive the corresponding menbership view event because the SST
happens after the event and will already include the effects of
all events ordered before it. The view then must be recovered from
the received state.

Minor renames and cleanups.

References codership/wsrep-lib#18

include/wsrep/view.hpp

@@ -97,6 +97,9 @@ namespace wsrep
         wsrep::view::status status() const
         { return status_; }
 
+        ssize_t capabilities() const
+        { return capabilities_; }
+
         ssize_t own_index() const
         { return own_index_; }
 
@@ -112,6 +115,11 @@ namespace wsrep
             return (members_.empty() && own_index_ == -1);
         }
 
+        /**
+         * Return member index in the view
+         */
+        int member_index(const wsrep::id& member_id) const;
+
         void print(std::ostream& os) const;
 
     private: