Add vector types and operations

Types:
+vint
+vdouble

Functions:
+ alloc_vint
+ free_vint
+ set_vint
+ copy_vint
+ alloc_vdouble
+ free_vdouble
+ setv_vdouble
+ copy_vdouble
+ dot_vdouble
+ add_vdouble
+ sum_vdouble