[Libreoffice] [REVIEW][3-5] Fix pivot table's date and number grouping, take 2

[Kohei Yoshida]

Hi there,

I've found a better way to fix it.  Attached is tailored specifically
for the 3-5 branch.

I'll port this fix to master separately since master has my earlier
commit that would make this patch not apply without adjusting.

Again, this fixes

https://bugs.freedesktop.org/show_bug.cgi?id=45067

Since we've already branched for 3.5.0, I'll need three sign-off's to
get this piece into 3.5.0 final.  Reviews and sign-off will be
appreciated.

Kohei

P.S. This NUMERIC flag was used exactly for this purpose prior to the
rework of the data pilot data cache code done by IBM/Sun back in the old
days (around the OOo 3.3 release period).  During the rework this check
was unfortunately removed, which probably introduced the original issue
I "fixed" for fdo#42169 (though apparently my fix was not entirely
correct).

-- 
Kohei Yoshida, LibreOffice hacker, Calc