Bugfix: GDS (and probably other greedy algorithms) can be trapped in an infinite loop due to rounding errors

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pcalg@213 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Improved test of dsep

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pcalg@214 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
adapt check to 32-bit


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pcalg@215 edb9625f-4e0d-4859-8d74-9fd3b1da38cb