tinyxml.rb: Use more canonical sources and patches.
tinyxml.rb: Use more canonical sources and patches.

Use the sourceforge tarball of tinyxml 2.6.2 and apply patches used
by debian. Also added my own patch for CMakeLists.txt

NikolausDemmel/homebrew-simulation,mikepurvis/homebrew-simulation,scpeters/homebrew-simulation,j-rivero/homebrew-simulation,osrf/homebrew-simulation,hgaiser/homebrew-simulation