A function, drovector_small::row, was added.
drovector_small*dgematrix_small function was added.
drovector_small::to_drovector() was added.
m2q function was added.
The return object type of inverse functions for symmetric matrices was chenged.
2D vector and matrix classes were added.
data storage of dgematrix_small was changed.
Files for small classes were organized.
update dquater
update dquater.hpp