Added library for Structured Diversity xform support. libStructDiv

.gitattributes

SConscript

libStructDiv/SConscript

libStructDiv/SConstruct

libStructDiv/include/filebased.h

libStructDiv/include/libStructDiv.h

libStructDiv/include/structured_diversity.h

libStructDiv/src/SConscript

libStructDiv/src/SConstruct

libStructDiv/src/filebased.cpp

libStructDiv/src/structured_diversity.cpp

libStructDiv/test/SConscript

libStructDiv/test/SConstruct

libStructDiv/test/simple_sd_driver.cpp