JuliaDB - Support for reading GZ file extension

@shashi, does _csvread from TextParse parsing abstract strings pose a problem for I/O streams?

I’m not sure if we should be discussing this here instead of on the Github issues I created, but since you brought it here I figured it’s alright.

@js135005 I am only worried about the GZ file extension at the moment.

Hi @shashi and @sdanisch, I’m winging the registration process on FileIO

gzip_magic = (0x1f8b)

function detectgzip(io)
    position(io) == 0 || return false
    seekend(io)
    len = position(io)
    seekstart(io)
    magic = Vector{UInt8}(length(gzip_magic))
    pos = position(io)
    read!(io, magic)
end

add_format(format"GZIP", [0x1f8b], ".gz")

I need to check if GZIP requires certain packages for I/O support.

I’ll build on this post before I actually make the PR, if you don’t mind.