Certain functions do not overload counterparts in LinearAlgebra

[BenjaminRemez]

Some functions (so far I noticed rank and inv) do not overload their counterparts in LinearAlgebra. using Modulo2, LinearAlgebra pollutes the namespace with e.g. two rank functions that must be disambiguated and thus one cannot dispatch on the type of the matrix. Is this intentional? If not, I am happy to commit a fix.

[matthias314]

inv is defined in Base, so there should be no problem. For rank, however, this is an oversight. I've just fixed it on master. Thanks for reporting it!