Panel API: add FCTL_SETACTIVEPANEL

git-svn-id: http://farmanager.com/svn/trunk@9868 72235d2c-c60c-0410-a47a-a0032694dc5d
Panel API: add FCTL_SETACTIVEPANEL

git-svn-id: http://farmanager.com/svn/trunk@9870 72235d2c-c60c-0410-a47a-a0032694dc5d