vdr-plugin-sudoku

Changes:

- Moved to http://projects.vdr-developer.org/projects/show/plg-sudoku.
- Changed repository from subversion to git.
- Removed subversion keywords ($Id).
- Added support for VDR >= 1.7.13 (Make.global).
- Added method Pos::interacts_with.
- Removed compatibility to VDR < 1.6.0.
- Converted documentation and source files to UTF-8.
- Added unit tests.
- Fixed segfault in History::current.
- Fixed null pointer handling in History::add.
- Updated url and email of the VDR project to tvdr.de.
- Updated Doxyfile to doxygen version 1.6.3.