Feature request: Provide convenience macros for the names

[stertingen]

I would like to propose providing the name of a detected component in a universal macro.

• BOOST_LANG_NAME shall be defined as detected language name
• BOOST_ARCH_NAME shall be defined as detected architecture name
  and so on for BOOST_COMP_NAME, BOOST_LIB_C_NAME, BOOST_LIB_STD_NAME, BOOST_LIB_OS_NAME, maybe for BOOST_PLAT_NAME.

The primary use case of this proposal is conveniently printing some build information to the user, allowing better bug reports.

I understand that some of those definitions are ambiguous, for example BOOST_ARCH_NAME could be defined to either BOOST_ARCH_X86_NAME or BOOST_ARCH_X86_64_NAME on x86-64.
In these cases, I would propose using either the 'leaf' names which are the most specific or the first ones detected.

[grafikrobot]

I like the idea. I'll see what I can come up with.