new method INetURLObject::getData() for data urls

Signed-off-by: Stephan Bergmann <sbergman@redhat.com>

Conflicts:
	tools/source/fsys/urlobj.cxx

Change-Id: I59b5b95cf9b65920ec04922fdb25e4228fd22995
Extend o3tl::heap_ptr to support arrays

Change-Id: I546afcb626e27f6f1115715829779fc0b657548e
Various INetURLObject::getData() fixes

Change-Id: I5eafd6250bbde7227dcc0447a4280b7741c320de