make the mark manipulation funcs use the caching
make the mark manipulation funcs use the caching

s:ClearMarks(), s:ClearAllMarks() and s:MarkNode() now use tell the
relevant path objects to update their mark cache

iff/dotfiles-old,tschundler/dotfiles,nywilken/dotfiles,tschundler/dotfiles,nywilken/dotfiles,iff/dotfiles-old,tschundler/dotfiles