Seems our Zip package is a bit too strict in checking archive
consistency - surely writing it out correctly is good, but rejecting
otherwise fine odf is not.

This reverts commit cd105c5a.
We can't use gb_Library_add_objcxxobjects here because
gb_ObjCxxObject_get_source has .mm suffix

To activate the layout and node dumping features in sw, set the SW_DEBUG
environement variable to anything before running the office. F12 will
then dump the layout as a layout.xml file in the working directory, and
Shift+F12 will dump the nodes structure as nodes.xml at the same place.

gb_SourceEnvAndRecurse_STAGE is unset in CustomTarget's make process
when the parent make has been started in sourced environment. This leads
to all sorts of "interesting" failures because the gbuild classes and
platform stuff are not loaded...

The breakage was due to the drawing layer re-work.  We do need to store
charts (or all OLE shapes with associated listening ranges) for later
registration regardless of anchor types.

Or else filtering of field members will not work correctly when the
field contains an empty name.

one test disabled because we first need to write a patch for our
internal cppunit

With this change, the automatic y-axis scaling should be more accurate
for stacked charts (i.e. stacked line, area, bar charts) with dates on
the x-axis.  The previous algorithm only calculated the max and min
y-values of the individual data, without taking into account the stacking
type when the x-axis type was date.