Four situations to handle:
1.) bidi same as previous setting: no adjust change
2.) no previous adjust: set appropriate default for this bidi
3.) previous adjust and bidi different from previous: swap adjusts
4.) previous adjust and no previous bidi: RTL swaps adjust

The previous method was pretty heavy-handed, especially when
clobbering the inherited ParaAdjust value. It essentially
only handled situation #2.

There are several commits that this one builds on or that
enhance it. Look in this bug 106174 and in bug 72560.

Change-Id: I07192ed93d50b07911cc8134a4ee57da87023d78
Reviewed-on: https://gerrit.libreoffice.org/57196
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>