- implemented axis inversion, real scales and zigzag mode, linescan for xfirst need more test data

git-svn-id: svn://svn.code.sf.net/p/gwyddion/code@16763 25697fe4-d644-49b8-9d30-be5465f2adf3
- implemented XY units oading

git-svn-id: svn://svn.code.sf.net/p/gwyddion/code@16764 25697fe4-d644-49b8-9d30-be5465f2adf3