Support pre-allocated array and configurable permutedims?

[findmyway]

This package is pretty neat and helpful!

Can we add some keyword arguments to the following function to reuse preallocated array and control whether to permute dims or not?

NPZ.jl/src/NPZ.jl

Lines 229 to 240 in 8834d3c

	function _npzreadarray(f, hdr::Header{T}) where {T}
	toh = hdr.descr
	if hdr.fortran_order
	@compat x = map(toh, read!(f, Array{T}(undef, hdr.shape)))
	else
	@compat x = map(toh, read!(f, Array{T}(undef, reverse(hdr.shape))))
	if ndims(x) > 1
	x = permutedims(x, collect(ndims(x):-1:1))
	end
	end
	ndims(x) == 0 ? x[1] : x
	end