"psppsheet" branch ready for wider testing

[Ben Pfaff]

I've pushed a new branch called "psppsheet" to the Git
repository.  This branch is (probably) the future of the data and
variable sheets in the PSPPIRE GUI.  I'd appreciate test builds
for Mac or Windows if you have time.

I'm starting to do nightly builds for GNU/Linux:
        http://pspp.benpfaff.org/~blp/pspp-psppsheet/

I'm appending a list of known issues.  Please report any other
bugs, suggestions, etc. to me (by email or in #pspp on freenode)
or the list.

Thanks,

Ben.


Both sheets
-----------

Using the arrow keys to move among column head buttons triggers "**
WARNING **: Internal button not found" if you move off-screen.


Data sheet
----------

Tab and Shift+Tab should skip over the "new variable" column to the
next or previous row.  (Reported by John Darrington.)

The case buttons at the head of each row should not scroll with the
rest of the row.  (Reported by John Darrington.)

The space to the right of the "new variable" column doesn't look like
the SPSS sheet or like a normal spreadsheet.  (Reported by John
Darrington and Michel Boaventura.)


Variable sheet
--------------

Double-clicking on variable names still processes a click after
switching sheets.

In the variable sheet changes effected by popup menus don't appear in
the sheet until the mouse rolls over that row.  (Reported by John
Darrington.)