- the \LyX macro is no longer fragile since r37164, therefore preamble code can go
- some intro cleanups and fixes to have an uniform layout for all language variants
- remove some obsolete text from Polish and Basque Additional.lyx versions
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_2_0_X@39349 a592a061-630c-0410-9148-cb99ea01b6c8