add vm port forwarding note/example in osx install docs

[cameron]

No description provided.

[SvenDowideit]

Can you please sign their commits following these rules: https://github.com/dotcloud/docker/blob/master/CONTRIBUTING.md#sign-your-work

Each commit in your PR must be signed in the following format:
Docker-DCO-1.1-Signed-off-by: Joe Smith <joe.smith@email.com> (github: github_handle)

Please rebase and sign each commit.

[cameron]

Thanks, all done.

[SvenDowideit]

mmm, @CameronBoehmer looks like travis doesn't like it - there's probably a space or a return out of place :(

can you add a little to point out that 49000..49900 are what Docker is likely to use then you use the -P option?

[cameron]

Good idea. Updated the example to use that range, as well.

[SvenDowideit]

LGTM, though I don't know that we should be linking to an external blog for the example

@metalivedev @jamtur01

[cameron]

On second thought, I agree. Link removed.

[metalivedev]

Thanks for the helpful tip. LGTM. Merging.

[Pyrolistical]

Why is this not done when the vm is created by the boot2docker script?

[cpuguy83]

@Pyrolistical Because this could have a hugely negative impact on the VM host.
In the latest version of boot2docker this is not even required anymore to get connectivity to the running containers.

[Hartimer]

Shouldn't this be

for i in {49000..49900}; do

(49000 instead of 4900)?