retain nctablet_ncplane() as deprecated alias

NEWS.md

@@ -3,7 +3,8 @@ rearrangements of Notcurses.
 
 * 1.7.5 (not yet released)
   * `ncreel_destroy()` now returns `void` rather than `int`.
-  * `nctablet_ncplane()` has been renamed `nctablet_plane()`.
+  * `nctablet_ncplane()` has been renamed `nctablet_plane()`. The former name
+    has been retained as a (deprecated) alias, to be removed in the near future.
 
 * 1.7.4 (2020-09-20)
   * All `_rgb_clipped()` functions have been renamed `_rgb8_clipped()`, to

include/notcurses/notcurses.h

@@ -2543,6 +2543,15 @@ API void* nctablet_userptr(struct nctablet* t);
 // Access the ncplane associated with nctablet 't', if one exists.
 API struct ncplane* nctablet_plane(struct nctablet* t);
 
+// deprecated predecessor of nctablet_plane()
+static inline struct ncplane*
+nctablet_ncplane(struct nctablet* t) __attribute__ ((deprecated));
+
+static inline struct ncplane*
+nctablet_ncplane(struct nctablet* t){
+  return nctablet_plane(t);
+}
+
 // The number of columns is one fewer, as the STRLEN expressions must leave
 // an extra byte open in case 'µ' (U+00B5, 0xC2 0xB5) shows up. PREFIXCOLUMNS
 // is the maximum number of columns used by a mult == 1000 (standard)