empty value and key names handling

git-svn-id: http://farmanager.com/svn/trunk@10299 72235d2c-c60c-0410-a47a-a0032694dc5d
grammar

git-svn-id: http://farmanager.com/svn/trunk@10301 72235d2c-c60c-0410-a47a-a0032694dc5d