This decouples the HPX compile time configuration from that of boost. This
removes the include order dependency between boost.config and hpx.

 - replaced all Boost.Config related macro definitions with the equivalent
   HPX macros
 - Boost config macros used for OS Thread API selection are untouched

Conflicts:
	hpx/util/detail/basic_function.hpp
	hpx/util/detail/function_template.hpp
	hpx/util/detail/unique_function_template.hpp

Conflicts:
	hpx/util/plugin/dll.hpp
	hpx/util/plugin/virtual_constructor.hpp
	hpx/util/thread_specific_ptr.hpp
	hpx/util/time_logger.hpp
	hpx/util/value_logger.hpp
	tests/performance/local/native_tls_overhead.cpp

Conflicts:
	hpx/lcos/local/dataflow.hpp
	hpx/runtime/naming/name.hpp
	hpx/runtime/serialization/access.hpp