SwXFrame::setPropertyValue: ignore setting ZOrder on TextBoxes

The ZOrder of a TextBox should be the ZOrder of the shape + 1, don't
allow setting it to something custom.

Change-Id: I17439aa9e494ae62ab80e178a8c5d90cea030351
SwTextBoxHelper::queryInterface: handle css::text::XTextRange as well

Change-Id: If56d7cab269a76062ee75bb1a9484f154b72c4d7
ODF loext:text-box import/export testcase

There is a lot more to test here, but for now just test that we can have
tables and rounded corners at the same time.

Change-Id: Ia9a4877202d1d040209f49a428b83633c58fc7c7
writerfilter: remove unused todo.xsl

Change-Id: Icd0ab345619fea029a63bafae9077a72cccc9852