slt-release-finish,start: gitflow release tools

These tools implement the gitflow release process, auto-generating the
changelog and setting the npm package version.

/to @rmg @bajtos 

I needed to cut a strong-supervisor release that was not from the head of origin/master, unsupported by hubflow, so I finally replaced it with a few lines of shell scripts, as threatened.
On Tue, Nov 4, 2014 at 11:29 PM, Miroslav Bajtoš
<notifications@github.com> wrote:
> I can add npm publish. Do you really want to publish without doing at least a manual check on what is getting published?
>
> What kind of check do you have in mind? I use to run npm test.

That npm pack doesn't include files you don't want, that the merges
were correct, that the changelog got updated correctly. Things like
that. I'm a little distrustful of tools that auto-publish something
I've never even seen, like the result of a merge.