Fix build with GCC 4.7 (and probably other C++11 compilers).

Fix build with GCC 4.7 (and probably other C++11 compilers).

User-defined literals introduced by C++11 break some previously valid
code, resulting in errors when building with GCC v4.7. For example:

  error: unable to find string literal operator 'operator"" PRIu64'

In particular, whitespace is now needed after a string literal and
before something that could be a valid user-defined literal.  See
"User-defined literals and whitespace" section at [1] for more details.

The patch adds spaces between string literals and macros.

[1] http://gcc.gnu.org/gcc-4.7/porting_to.html