Revert the box alignment part of 8010b90c

Revert the box alignment part of 8010b90c

The horizontal alignment changes caused a regression for documents in older
formats. This could have been fixed by adding the following lines to the
format entry for 489 in development/FORMAT:

	Previously, the horizontal position was ignored except for the
	following parameter combinations:
	- fixed width and type Boxed and without inner box
	- fixed width and any type   and with    inner box and with makebox
	Now, it is also used for the parameter combination below:
	- makebox is not used and not (type Boxed and without inner box)

and a corresponding conversion to convert_BoxFeatures() in
lib/lyx2lyx/lyx_2_2.py. However, it was decided to revert the box alignment
changes instead: The box alignment can contradict the paragraph alignment. A
better way to avoid the additional space that can be created by paragraph
alignment (which was the motivation for implementing box alignment) is the
same as for table cells (see noTrivlistCentering() in src/Paragraph.cpp).
This would be a file format change and it is too late now for 2.2.0.

See http://www.mail-archive.com/lyx-devel@lists.lyx.org/msg188147.html for the
complete discussion (subject "Regression in lyx2lyx box alignment").