Log Message:
Changes 2.16.1:
- Fixed bugs
- Improvements to PHP binding
- Improvements to OCAML binding
- Make regression tests run from the build tree, rather than require
  installation
- Repair freetype detection on RedHat-7 (Yes, people still use it!!)
- Fix zoom-at-mouse-location in -Txlib and -Tgtk
- Fix some dotty regressions

Changes 2.16:
- Fixed bugs
- new regression test suite
- new cgraph library (will eventually replace graph and agraph)
- add "image" and "imagescale" for simpler support for \ 
images in nodes
- add "tab" "box3d" and "component" shapes
- replace arith.h in distro
- add functions to access version info to avoid need for gvcint.h
- Fix problem with irregular character spacing at 96dpi in pango/cairo output
  formats.
- Add gdk_pixbuf plugin providing: .bmp .ico .jpg .png .tif
- Add DevIL plugin providing: .bmp .jpg .png .tif .tga
- Extend GD plugin to provide a backend to cairo for: .gif .jpg .png .gd .gd2
  .wbmp  <- gifs are now antialiased
- Rework plugin framework to separate device from renderer, and to autoload
  load dependendent plugins
- show defaults in output from: ./configure --help
- add more info to dot -v  and dot -v2 debug outputs
- various issues with CR/LF in windows, but not in binary outputs.