Fixed:

• Fix and error, where a non-redundant linearity could be considered redundant.
• Fix an optimization error in ViaShooting code so that the linear programs are now much smaller.
• Fixed memory leaks in the redundancy code.
• Updated version number in dd_DDVERSION define.

Fixed:

• extern C block in cdd.h header for C++ (thanks to @jengelh)

• header files are now installed to PREFIX/include/cddlib to avoid clashes
  with other libraries.
• configuration file for pkg-config added: assuming cddlib installed in
  known to pkg-config, "pkg-config --cflags cddlib" etc will
  work. (Otherwise, one would need PKG_CONFIG_PATH=/lib/pkgconfig).

• modernized autotooling
• mirrored code on GitHub
• introduced cddexec as a replacement of cdd_both_reps that many distributions packaged
• made randomization portable
• fix representation type in dd_MatrixAppendTo