Sunburst tree display is improved.
fixed a bug in png export.
hide/show all formulas for proofs is added.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1935 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Sorry, forgot one file :)

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1936 85d21ef8-add0-11de-ae77-5bfb9c5a3f34