Change capital variable names to lowercase

[AdamMajer]

Capitals clash by convention with #define, and in this case
VERSION clashes with GNU Autotools. This means projecting using
GNU Autotools and Boost::Test library no longer compile.

To fix this problem and possibly others down the line,
downcase all the string constants in the rt::runtime_config
namespace. (trac 12748)

[AdamMajer]

As to obvious "why not just change VERSION to something else?" - so it's consistent.

[raffienficiaud]

Thanks for the PR. While I understand for the VERSION macro clash, I would like to keep this minimal. So I would rather rework your PR for fixing this issue and making those variables/macros more boost.test specific.

[raffienficiaud]

Merged to branch origin/topic/12748-VERSION-macro-clashes, thanks

[AdamMajer]

Thanks fine too. Thank you.

[raffienficiaud]

Merged to develop, closing.