Vectors should be compatible with columns wherever possible

[ghost]

You need to double-transpose vectors to make them into 1-column matrices so that
you can add them to 1-column matrices or multiply them with one-row matrices (on
either side).

[ViralBShah]

We need a general way to address this throughout our array implementation.

[JeffBezanson]

I tried the following cases and they all worked:

a=rand(3,3); v= rand(3);
a[:,1]=v
a[1,:]=v
a[:,1]+v
a[1,:]*v
v*a[1,:]

And this works but there's an issue saying maybe it shouldn't:

a[1,:]+v

Can we find any examples of cases that are still failing?

[JeffBezanson]

Due to our improved error checking, this happens:

julia> [1 2 3]' + [1,2,3]
argument dimensions must match
in +, /home/jeff/src/julia2/julia/j/abstractarray.j:203

Should we define dims_match(a,b) that allows dims to match in the presence of trailing ones?

[JeffBezanson]

Duplicate of #231.