Release version 15.

* Support for MCST LCC compiler.
* New HEDLEY_DIAGNOSTIC_DISABLE_UNUSED_FUNCTION macro.
* Assorted bug fixes and enhancements.

Update NEWS for v14

Add test for HEDLEY_CONCAT3 macro.

Release version 12:

* New macros:
  * HEDLEY_WARN_UNUSED_RESULT_MSG
  * TI compilers:
    * HEDLEY_TI_CL2000_VERSION and HEDLEY_TI_CL2000_VERSION_CHECK
    * HEDLEY_TI_CL430_VERSION and HEDLEY_TI_CL430_VERSION_CHECK
    * HEDLEY_TI_ARMCL_VERSION and HEDLEY_TI_ARMCL_VERSION_CHECK
    * HEDLEY_TI_CL6X_VERSION and HEDLEY_TI_CL6X_VERSION_CHECK
    * HEDLEY_TI_CL7X_VERSION and HEDLEY_TI_CL7X_VERSION_CHECK
    * HEDLEY_TI_CLPRU_VERSION and HEDLEY_TI_CLPRU_VERSION_CHECK
  * HEDLEY_TI_VERSION is now only set for MCU compilers after their
    versions were harmonized.
* Assorted bug fixes and enhancements

Release version 11:

* New macros:
  * HEDLEY_HAS_CPP_ATTRIBUTE_NS
  * HEDLEY_DIAGNOSTIC_DISABLE_UNKNOWN_CPP_ATTRIBUTE
  * HEDLEY_NO_ESCAPE
  * HEDLEY_NULL
* Assorted bug fixes and enhancements

Update NEWS for v10.

Release version 9:

* New macros:
  * HEDLEY_PREDICT
  * HEDLEY_PREDICT_TRUE
  * HEDLEY_PREDICT_FALSE
  * HEDLEY_UNPREDICTABLE
  * HEDLEY_CONSTEXPR
  * HEDLEY_ASSUME
  * HEDLEY_FLAGS_CAST
* Most tests now use HEDLEY_GCC_* instead of HEDLEY_GNUC_*
* Intel C/C++ Compiler implementations now go down to version 13
  instead of version 16.
* New compiler support:
  * CompCert
  * Pelles C
* Add SPDX identifier
* Assorted bug fixes and enhancements

Release version 8.

Release version 7.

Release vesion 6.

 * New macros:
   * HEDLEY_UNREACHABLE_RETURN
 * New compiler support:
   * Tiny C Compiler
   * Digital Mars C/C++ Compiler