readme: fixed mistakes
src: added instance method 'Vector.set()'
readme: updated and added 'Vector.set()' api
src: added instance method 'Vector.get()'
src: avoided Complex using std::shared_ptr
src: modified some codes
src: added some files for checking types
src: abstracted some codes for Vector
src: added instance method 'Vector.get()'
lint: added some files

disable [build/c++11]
readme: added Vector apis and updated apis
test: updated Vector testings