Update README.developer and ReleaseNotes

Tell developers about upcoming C standard change
Rework some of the text in relnote

Still need something about support term of 4.7 - placeholder at top
  of ReleaseNotes_4.7

Should go into both 4.7 & master

README.developer

@@ -1,6 +1,6 @@
 Hamlib - (C) Frank Singleton 2000 (vk3fcs@ix.netcom.com)
          (C) Stephane Fillod 2000-2011
-         (C) The Hamlib Group 2000-2025
+         (C) The Hamlib Group 2000-2026
 
 Primary site for the latest development version of Hamlib is
 https://github.com/Hamlib/Hamlib
@@ -12,7 +12,7 @@ See README.md for frontend/backend outline.
 See README.betatester for background on testing Hamlib.
 
 
-The library provides functions for both radio, rotator, and amplifier control,
+The library provides functions for radio, rotator, and amplifier control,
 and data retrieval from the radio, rotator, or amplifier.  A number of functions
 useful for calculating distance and bearing and grid square conversion are
 included.
@@ -700,7 +700,7 @@ GUI development. I would like to see some GTK or Qt apps that use the Hamlib
 APIs so they can be used by end users as a nice part of the Ham shack.
 
 Starting points (not exhaustive):
-    Fldigi, CQRlog, gmfsk, gpredict, grig, klog, kontakt, ktrack, xlog
+    Fldigi, CQRlog, gmfsk, gpredict, grig, klog, kontakt, ktrack, Not1MM, xlog
 
 
 8. Contributing code
@@ -754,8 +754,8 @@ Hamlib should also compile with the following common compilers:
 
 Portability issues to watch:
 
-    * C99 is probably (in 2016) a reasonable target--C11/C17 minimum is being
-      considered for Hamlib 5.
+    * C99 is probably (in 2016) a reasonable target--C11/C17 will be the
+      requirement for Hamlib 5.
     * little vs. big endian systems (use shifts or adhoc functions)
     * printf/scanf of 64bit int: use PRIll (cast value to int64_t) and SCNll
     * printf/scanf of freq_t: use PRIfreq and SCNfreq

ReleaseNotes_4.7.md

@@ -1,12 +1,13 @@
-# HAMLIB 4.7 - Release Notes (WIP)                        2025-12-01(?)
-
-*This is very much a first cut - nothing is set in concrete or inviolate - n3gb*
+# HAMLIB 4.7 - Release Notes                        2026-02-15
 
 This release brings new equipment support, bug fixes/code cleanups, and some
 changes to ease transition to 5.0
 
+**Support term changes go here**
+
 ## New equipment support
-- Yaesu FTX-1 Optima/Field - Work in progress; testers welcome.
+- Icom IC-7300MK2
+- Yaesu FTX-1 Optima/Field
 - Drake R8/R8A/R8B - new, revised backend
 - AF6SA WRC rotator
 - GUOHETEC PMR-171 & Q900 moved to separate backend
@@ -19,7 +20,7 @@ changes to ease transition to 5.0
   [#924](https://github.com/Hamlib/Hamlib/issues/924).
 - Functions `rig_set_trn()` & `rig_get_trn()` deprecated; operation now handled internally.
 - Documentation brought up to date.
-- (TBD)
+- Many bug fixes - see NEWS for summary, `git log` or `gitg`/`gitk` for details.
 
 ## Build/install changes
 - POSIX threads(PTHREADS) support required
@@ -39,8 +40,8 @@ HAMLIB 5.0 will move many data items/structures out of rig_struct into separate
 buffers. See issues [#487](https://github.com/Hanlib/Hamlib/issues/487),
 [#1445](https://github.com/Hamlib/Hamlib/issues/1445), and
 [#1420](https://github.com/Hamlib/Hamlib/issues/1420). This changes many of
-the methods for accessing HAMLIB internal data. HAMLIB 4.7 marks these old methods as
-"Deprecated", and supplies macros to use for forward compatibility.
+the methods for accessing HAMLIB internal data. HAMLIB 4.7 supports both methods,
+supplying macros to use for forward compatibility.
 
 ### Include files
 Along with the moves to separate storage, the definitions of these data structures
@@ -51,5 +52,5 @@ Preliminary versions of these files are also part of 4.7 for pre-emptive use.
 
 ### The good news
 If your application only calls the Hamlib API routines, then nothing needs to change.
-If your application only uses configuration items like names, speeds, etc, it may be
-easiest to change over to using rig_set_conf(). and let Hamlib handle the internals.
+If your application only uses configuration items like file/port names, speeds, etc, it
+may be easiest to change to using rig_set_conf(). and let Hamlib handle the internals.