- reworked drawing all potentially semi-transparent things on top of data
  by the push-group pop-group-to-source mechaism
- this enables combining outlines with transparency


git-svn-id: svn://svn.code.sf.net/p/gwyddion/code/trunk/gwyddion@16699 25697fe4-d644-49b8-9d30-be5465f2adf3
- finished outline drawing implementation for remaining selection types


git-svn-id: svn://svn.code.sf.net/p/gwyddion/code/trunk/gwyddion@16700 25697fe4-d644-49b8-9d30-be5465f2adf3