Dont redraw the whole tree when checkbox was checked/unchecked

This was causing delays and was resulting in saving incorrect data when checking/unchecking lots of nodes in the tree very fast.  We dont need to redraw the whole tree to change the text color of checked/unchecked nodes and it's children in the tree to show user the changes in the tree. Fixed to only render the node that was checked/unchecked and it's children to show differences in blue color.

https://bugzilla.redhat.com/show_bug.cgi?id=1153047
https://bugzilla.redhat.com/show_bug.cgi?id=1145799
Merge pull request #852 from h-kataria/dont_redraw_dynatree_when_changing_node_text_color

Dont redraw the whole tree when checkbox was checked/unchecked