Fixes for BOOST_PP_SEQ_REMOVE when the seq is its maximum size and has its last element removed. Also updated seq tests.

This reverts commit dc61cc13.

Disallow variadic macro support for versions below 12.4, since that is the first version with C++11 support.

For Oracle C++ do not automatically turn off variadic macro support for version 12.3 or higher, since those versions can support C++11.

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.