5.2 rc2 tarball now available

[sfeam <sf...@us...>]

One month of -rc1 turned up one serious bug, a couple of minor bugs that 
were easily triggered, and a bunch of odd corner cases found by fuzz-testing
that could only be hit by invalid command syntax or strange input data.
Not too bad.

So here is -rc2

Release Notes date: 03-Jul-2017

CHANGES SINCE rc1
=================
* FIX: terminal initialization must complete before executing ~/.gnuplot
* FIX: incorrect clipping of polar border and raxis
* FIX: add sanity checks to detect and handle various types of bad input data
       or command syntax found by fuzz-testing
* FIX: windows terminal (various minor tweaks)


	Ethan