returns zero matrices with dimensions defined by paramters

supports Matrix ==> Vector types

…_column_* methods

This keeps the index numbering system consistent with direct immutable and mutable Matrix index data access

…thod

…trix addition

binary subtraction operator overload

…2 and f64 types

includes unit tests of Complex<i32> and Complex<f64>

addresses https://rust-lang.github.io/rust-clippy/master/index.html#return_self_not_must_use clippy lint fail that was fixed on Vector struct in #82

supports simple initialization of matrices with array-like row vector syntax

Implement matrix! macro

…Into<Vec<T>> types

instead of Vec<T> types