Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import tex-a2ping-2.77p as graphics/tex-a2ping.

a2ping is a Perl script command line utility written for Unix that
converts many raster image and vector graphics formats to EPS or PDF
and other page description formats.  Accepted input file formats are:
PS (PostScript), EPS, PDF, PNG, JPEG, TIFF, PNM, BMP, GIF, LBM, XPM,
PCX, TGA.  Accepted output formats are: EPS, PCL5, PDF, PDF1, PBM,
PGM, PPM, PS, markedEPS, markedPS, PNG, XWD, BMP, TIFF, JPEG, GIF,
XPM.  a2ping delegates the low- level work to Ghostscript (GS),
pdftops and sam2p.  a2ping fixes many glitches during the EPS to EPS
conversion, so its output is often more compatible and better
embeddable than its input.