Convert binary .dfm files to plain text.

For power_calibration and stimeditor_dragdrop, changes were made to
the GUI (stored in *.dfm files); these are usually text, but MAIN.dfm
and WAVGEN.dfm were binary (presumably because of bitmaps they contain).
I am converting to plain text to facilitate merging (from upgraded
origin/master into my own branches, and then eventually from those
branches back into master).