add option to build without blenders default avi codec.

CMakeLists.txt

SConstruct

build_files/cmake/config/blender_lite.cmake

source/blender/CMakeLists.txt

source/blender/blenkernel/CMakeLists.txt

source/blender/blenkernel/intern/writeavi.c

source/blender/imbuf/CMakeLists.txt

source/blender/imbuf/intern/IMB_anim.h

source/blender/imbuf/intern/anim_movie.c

source/blender/imbuf/intern/indexer.c

source/blender/imbuf/intern/util.c