clip ground fill 'extensions' to pcb border

git-svn-id: http://fritzing.googlecode.com/svn/trunk@6914 85f94c43-f63a-0410-9d22-21439860c375
keepout ui tweak

git-svn-id: http://fritzing.googlecode.com/svn/trunk@6915 85f94c43-f63a-0410-9d22-21439860c375