Log Message:
Update to 2015.02.24:

* Noteworthy changes in release 2015.02.24 (2015-02-24) [stable]

  AX_CHECK_ENABLE_DEBUG now uses $ax_is_release as default for IS-RELEASE.

  AX_IS_RELEASE now supports micro-version policies.

  Portability of AX_CXX_COMPILE_STDCXX_0X has been improved.

  AX_PROG_HAXE_VERSION is a new macro to detect the presence of Haxe
  <http://haxe.org>.

  AX_COMPILER_FLAGS has undergone extensive re-factoring.

  AX_COMPILER_FLAGS_CXXFLAGS is a new macro that tests available C++ compiler
  warnings.

  AX_CXX_COMPILE_STDCXX_11 can now test for SFINAE with template aliases.

  AX_APPEND_FLAG: Fix a regression introduced in the previous release.