- added a simple function for mask thinning
- often needs some opening/closing preprocessing, but then it can create nice
  skeletons


git-svn-id: svn://svn.code.sf.net/p/gwyddion/code/trunk/gwyddion@16847 25697fe4-d644-49b8-9d30-be5465f2adf3
- some more 2.40 news


git-svn-id: svn://svn.code.sf.net/p/gwyddion/code/trunk/gwyddion@16848 25697fe4-d644-49b8-9d30-be5465f2adf3