+Change data type of field counts to pb_size_t
+---------------------------------------------
+**Rationale:** Often nanopb is used with small arrays, such as 255 items or
+less. Using a full *size_t* field to store the array count wastes memory if
+there are many arrays. There already exists parameters *PB_FIELD_16BIT* and
+*PB_FIELD_32BIT* which tell nanopb what is the maximum size of arrays in use.
+
+**Changes:** Generator will now use *pb_size_t* for the array *_count* fields.
+The size of the type will be controlled by the *PB_FIELD_16BIT* and
+*PB_FIELD_32BIT* compilation time options.
+
+**Required actions:** Regenerate all *.pb.h* files. In some cases casts to the
+*pb_size_t* type may need to be added in the user code when accessing the
+*_count* fields.
+
+**Error indications:** Incorrect data at runtime, crashes. But note that other
+changes in the same version already require regenerating the files and have
+better indications of errors, so this is only an issue for development
+versions.
+
+Renamed some macros and identifiers
+-----------------------------------
+**Rationale:** Some names in nanopb core were badly chosen and conflicted with
+ISO C99 reserved names or lacked a prefix. While they haven't caused trouble
+so far, it is reasonable to switch to non-conflicting names as these are rarely
+used from user code.
+
+**Changes:** The following identifier names have changed:
+
+ * Macros:
+
+ * STATIC_ASSERT(x) -> PB_STATIC_ASSERT(x)
+ * UNUSED(x) -> PB_UNUSED(x)
+
+ * Include guards:
+
+ * _PB_filename_ -> PB_filename_INCLUDED
+
+ * Structure forward declaration tags:
+
+ * _pb_field_t -> pb_field_s
+ * _pb_bytes_array_t -> pb_bytes_array_s
+ * _pb_callback_t -> pb_callback_s
+ * _pb_extension_type_t -> pb_extension_type_s
+ * _pb_extension_t -> pb_extension_s
+ * _pb_istream_t -> pb_istream_s
+ * _pb_ostream_t -> pb_ostream_s
+
+**Required actions:** Regenerate all *.pb.c* files. If you use any of the above
+identifiers in your application code, perform search-replace to the new name.
+
+**Error indications:** Compiler errors on lines with the macro/type names.
+