make SvXMLImport capable of mixing fast- and slow- contexts adhoc

so I can convert even *ImportContext subclasses in the middle of
a context stack, and thus break the cyclic dependency nature
of the writer import.

and adjust the xmlimport loplugin for the new rules.

As a consequence of the loplugin:xmlimport's checking, we remove
a bunch of now unnecessary overrides of startFastElement.

Change-Id: I97464522ede8ec5e345e928cdafa4b18364b1b80
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/104730
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

0 files changed, 0 insertions, 0 deletions