Layout fixes

* remove hardcoded margin and spacings
* QLayout::addItem -> QLayout::addLayout
* some QGridLayout -> QFormLayout
* fix double margin issues

I hope I did not break anything, as it is often not obvious for me
how I can invoke all these dialogs. If you find regressions, CC me,
as I am not subscribed to kde-pim or kde-commits.

CCMAIL:kde-pim@kde.org

svn path=/trunk/KDE/kdepimlibs/; revision=1008949