Fixed problem when repetitions go past 256 and the 257th loop op returns that the repetitions are finished.

When the Intellisense compiler is being used wihin the Visual Studio IDE, both __EDG__ and __INTELLISENSE__ are defined along with the usual VC++ predefines. This change adjusts the Boost PP configuration to take into account that situation.

When using clang variadic macro support is now dependent on the C or C++ version system, and not automatically turned on in all situations. This reduces clang warnings.

Create metadata file.

Changed BOOST_PP_EMPTY to only use the variadic version when not VC++. Corrected others to use local version of EMPTY.