make sure Derivative[g(x),x,2] returns ? not g'(x)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30527 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
allow Derivative[sin(t)] and Derivative[sin(t),2]

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30528 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3831  attaching view stops animation, detaching view starts them.

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30529 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e