Bug fix: correctly redraw a Row containing and inset which Dimension slightly changed...

Bug fix: correctly redraw a Row containing and inset which Dimension slightly changed. This replace the need for the former leftEdgeFixed boolean in rowpainter.C:paintPar() before the removal of the wide() hack in revision 19834.

* Inset::dimension(): access to dim_

* TextMetrics::redoParagraph(): don't trust Inset::metrics() returned boolean as the internal dimension is changed down in the inheritance chain for InsetFoot->InsetCollapsable->InsetText.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@19838 a592a061-630c-0410-9148-cb99ea01b6c8