Version bump to 2.4.0

[Joel Sherrill]

On 03/29/2016 04:41 PM, Jeff Johnston wrote:
> Due to the recent feature test overhaul affecting some projects using
> newlib, a version bump was warranted so that a test could be made when
> including header files.
>
> I have bumped up the version to 2.4.0 and will be posting a snapshot build
> shortly.
Thanks. We will see if we can switch RTEMS development tools
to this snapshot and the latest GCC snapshot once it is out.
If not, then we may request a bug fix bump. We want to get these
changes out to users for testing.

I just checked and I don't appear to have any uncommitted patches.

--joel