more or less rewritten select option handling; many more detailed tests added

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9760 5f5364db-9458-4db8-a492-e30667be6df6
style fix

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9761 5f5364db-9458-4db8-a492-e30667be6df6