pre-release Testing tarball for version 5.0.5

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

If no last-minute problems are found, I plan to release gnuplot 5.0.5
(version 5.0 patchlevel 5) in a week or so.

I have uploaded a source tarball for testing.
You can find it in the "testing" file folder on SourceForge:

      https://sourceforge.net/projects/gnuplot/files/gnuplot/testing/

This patchlevel 5.0.5 incremental release includes
==================================================

* NEW allow filename completion for system commands and pipes (backport from 5.1)
* NEW option to plot with labels {rotate variable}
* NEW command "set minussign"
* NEW stats command "name" option now accepts "columnheader" or "columnheader(N)"
* NEW command option "set colorbox invert"
* CHANGE qt terminal force selection of outline font rather than bitmap font
* CHANGE post terminal simplex/duplex output depends on PostScript level setting
* CHANGE improved autoscaling of plot "with boxes"
* CHANGE qt terminal sets TERM_POLYGON_PIXELS to avoid aliasing artifacts
* CHANGE all stats and fit commands skip header records if "autotitle columnhead"
* FIX various bugs affecting matrix data plotted "with image"
* FIX Do not confuse EOF with 8-bit character 0x177 (E.g. in Cyrillic encodings).
* FIX use blank line rather than 'u' flag in "set table" output of smoothed data
* FIX regression in rendering 'plot ... matrix every ... with image'
* FIX order dependence of "fillcolor" keyword in plot commands
* FIX svg - better vertical justification of rotated text
* FIX wxt - file export widget correctly handles inactive plots
* FIX qt - preserve leading and trailing whitespace in enhanced text strings

	Ethan