Fix placement of amplifier fields for land units

Change X and Y values for the AF, T, X and Z text amplifier fields for
land units. Checked against the latest 2525D document.
Fix placement of amplifier field for subsurf. unit

Change Y value for the H amplifier field for subsurface units
Add depth amplifier field for subsurface unit

The subsurface unit is missing the X text amplifier field for depth.
Merge pull request #130 from kjellmf/master

Modify placement of some text amplifier fields for land and subsurface units